[BostonCard]

OK, here’s the situation:

Western Michigan up 12-7 on Michigan; Michigan tries for a Hail Mary that goes out the end zone as time seemingly expires.  “After further review” the refs add one second back to the clock, Michigan tries again, scores a touchdown and wins 13-12.

https://x.com/awfulannouncing/status/209...86880?s=61

Honestly, I find it pretty indefensible, but perhaps I’m missing something in the rules.

BC

[BostonCard]

OK, here’s the situation:

Western Michigan up 12-7 on Michigan; Michigan tries for a Hail Mary that goes out the end zone as time seemingly expires.  “After further review” the refs add one second back to the clock, Michigan tries again, scores a touchdown and wins 13-12.

https://x.com/awfulannouncing/status/209...86880?s=61

Honestly, I find it pretty indefensible, but perhaps I’m missing something in the rules.

BC

[BostonCard]

Here’s the explanation:

https://x.com/bigten/status/2096460445213217097?s=61

BC

[BostonCard]

Here’s the explanation:

https://x.com/bigten/status/2096460445213217097?s=61

BC

[M T]

Here’s the explanation:

https://x.com/bigten/status/2096460445213217097?s=61

BC

I can believe that the time shown in a scorebox or overlaid on the TV is not what the game clock shows.  I often see that in WBB games where you see both the physical clock and the time put on the screen by the broadcaster.  

But in this case, both the Big Ten review system and the broadcast claim to be showing the stadium clock, each also showing the play.
The Big Ten indicates the two separate cameras were synced some 4 or 5 hours earlier.   The broadcaster is using (live) video processing to insert the clock into the broadcast feed.

Eighty-five minutes prior to the game, all broadcast cameras used for the replay system, including the camera on the game clock, are synced using a strobe system to ensure all cameras are aligned.

That doesn't clarify why what they saw are "aligned" (I would say "synced") at the end of the game. I sorta suspect that they are feeding each camera to some digital recording device, and each view we see at the end shows the same position (frame number) in the two recordings. But what if a few frames got lost during transmission to the recording device?

For the inset, I could imagine that the inset image is a frame behind or maybe ahead due to processing the two into one image, but I don't know.  (But in this case, the Big Ten seems to be asserting that the inset clock was several frames ahead of the main image.)  Certainly it would be easy to demonstrate the accuracy of the inset by turning the main camera to the stadium clock while the inset is also showing the ticking clock.

Likewise, the replay system could also view a ticking clock after the end of (or during) the game with all cameras to confirm whether or not there is a discrepancy.

I would have more confidence in the Big Ten review system if all the cameras had a common physical sync signal inserting a frame count to all cameras, and the frame number was shown in all views.  Indeed, why not insert the game clock time onto every frame as meta information?  Or, almost equivalently, have each frame contain the GPS time in, say, microseconds.

Heck, the recording system should be able to record the time the signal arrives from each camera.  But notice that is vulnerable to errors.  I am sure all this is done over a network to the recording system and there are delays, out-of-order arrivals, and lost packets or retransmits that can happen on such systems.  (Such delays also apply to the broadcast main image and inset image.)

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

I certainly expect someone (ESPN?) will do a detailed error analysis of each system to understand how apparent errors crept into at least one of them.  Annotating each frame with its GPS time as the frame is processed by the camera is probably the best way to avoid such errors.

If I were a betting man, I'd bet that the broadcaster was more likely to have smaller errors.  (A lot can happen in 5 hours.)

[M T]

Here’s the explanation:

https://x.com/bigten/status/2096460445213217097?s=61

BC

I can believe that the time shown in a scorebox or overlaid on the TV is not what the game clock shows.  I often see that in WBB games where you see both the physical clock and the time put on the screen by the broadcaster.  

But in this case, both the Big Ten review system and the broadcast claim to be showing the stadium clock, each also showing the play.
The Big Ten indicates the two separate cameras were synced some 4 or 5 hours earlier.   The broadcaster is using (live) video processing to insert the clock into the broadcast feed.

Eighty-five minutes prior to the game, all broadcast cameras used for the replay system, including the camera on the game clock, are synced using a strobe system to ensure all cameras are aligned.

That doesn't clarify why what they saw are "aligned" (I would say "synced") at the end of the game. I sorta suspect that they are feeding each camera to some digital recording device, and each view we see at the end shows the same position (frame number) in the two recordings. But what if a few frames got lost during transmission to the recording device?

For the inset, I could imagine that the inset image is a frame behind or maybe ahead due to processing the two into one image, but I don't know.  (But in this case, the Big Ten seems to be asserting that the inset clock was several frames ahead of the main image.)  Certainly it would be easy to demonstrate the accuracy of the inset by turning the main camera to the stadium clock while the inset is also showing the ticking clock.

Likewise, the replay system could also view a ticking clock after the end of (or during) the game with all cameras to confirm whether or not there is a discrepancy.

I would have more confidence in the Big Ten review system if all the cameras had a common physical sync signal inserting a frame count to all cameras, and the frame number was shown in all views.  Indeed, why not insert the game clock time onto every frame as meta information?  Or, almost equivalently, have each frame contain the GPS time in, say, microseconds.

Heck, the recording system should be able to record the time the signal arrives from each camera.  But notice that is vulnerable to errors.  I am sure all this is done over a network to the recording system and there are delays, out-of-order arrivals, and lost packets or retransmits that can happen on such systems.  (Such delays also apply to the broadcast main image and inset image.)

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

I certainly expect someone (ESPN?) will do a detailed error analysis of each system to understand how apparent errors crept into at least one of them.  Annotating each frame with its GPS time as the frame is processed by the camera is probably the best way to avoid such errors.

If I were a betting man, I'd bet that the broadcaster was more likely to have smaller errors.  (A lot can happen in 5 hours.)

[newguy]

It would be interesting if the headline in tomorrow's Michigan Daily reads, "NCAA Awards Game to Western Michigan"

[newguy]

It would be interesting if the headline in tomorrow's Michigan Daily reads, "NCAA Awards Game to Western Michigan"

[82lsju]

I'm pretty sure if the roles were reversed the WMU would not have gotten a second chance at a Hail Mary......

[82lsju]

I'm pretty sure if the roles were reversed the WMU would not have gotten a second chance at a Hail Mary......

[cardcrimson]

[quote="BostonCard" pid='452756' dateline='1788671782']

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

Inadmissible, your honor. I seem to recall a photo taken by a student in the stands from a certain game in the early eighties showing a ref signaling a certain play dead. Also seem to recall video showing at least two forward "laterals" and a knee or two down. At this point, the game stolen and over. . . .

Biggest hose job since November 20th, 1982

[cardcrimson]

[quote="BostonCard" pid='452756' dateline='1788671782']

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

Inadmissible, your honor. I seem to recall a photo taken by a student in the stands from a certain game in the early eighties showing a ref signaling a certain play dead. Also seem to recall video showing at least two forward "laterals" and a knee or two down. At this point, the game stolen and over. . . .

Biggest hose job since November 20th, 1982

[needle]

Anyone with a stopwatch and the ability to pause a replay of the final snap can definitely determine whether the officials made an error.

Just before the last play, the refs announced to the game clock operator there should be 9 seconds remaining.

Watch the replay. When the ball is snapped, start your stopwatch. At 8 seconds on your stopwatch, pause the replay. Then, look at the video to see where the ball is.

You will see the ball right between the W. Michigan defender's hands. Officials made the right call (assuming they were right to add the extra second *before* the snap). Case closed.

[needle]

Anyone with a stopwatch and the ability to pause a replay of the final snap can definitely determine whether the officials made an error.

Just before the last play, the refs announced to the game clock operator there should be 9 seconds remaining.

Watch the replay. When the ball is snapped, start your stopwatch. At 8 seconds on your stopwatch, pause the replay. Then, look at the video to see where the ball is.

You will see the ball right between the W. Michigan defender's hands. Officials made the right call (assuming they were right to add the extra second *before* the snap). Case closed.

[d4cohn]

[quote="BostonCard" pid='452756' dateline='1788671782']

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

Inadmissible, your honor. I seem to recall a photo taken by a student in the stands from a certain game in the early eighties showing a ref signaling a certain play dead. Also seem to recall video showing at least two forward "laterals" and a knee or two down. At this point, the game stolen and over. . . .

Biggest hose job since November 20th, 1982

https://en.wikipedia.org/wiki/Fifth_Down_Game_(1990)

[d4cohn]

[quote="BostonCard" pid='452756' dateline='1788671782']

I wouldn't be surprised if some people in the stadium recorded it with their phones so that the stadium clock and the touch were both in the same view.  It will be interesting if someone comes out with such a view.  But considering those in the stadium are almost entirely Michigan fans, I doubt they will look at it closely.

Inadmissible, your honor. I seem to recall a photo taken by a student in the stands from a certain game in the early eighties showing a ref signaling a certain play dead. Also seem to recall video showing at least two forward "laterals" and a knee or two down. At this point, the game stolen and over. . . .

Biggest hose job since November 20th, 1982

https://en.wikipedia.org/wiki/Fifth_Down_Game_(1990)

[newguy]

i was impressed when the ACC showed the replay booth during their ruling that Flintoft's punt touched our guy's toe, before bouncing off Miami's player.
that's the sort of transparency i'd like to see from other conferences.

[newguy]

i was impressed when the ACC showed the replay booth during their ruling that Flintoft's punt touched our guy's toe, before bouncing off Miami's player.
that's the sort of transparency i'd like to see from other conferences.

[BostonCard]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

[BostonCard]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

[cardcrimson]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

That's a cover up for you. So the stadium clock is off, seriously? I guess we should assume the 25 (or 40) second clock is off as well. Soon we'll be having video replays to determine if a play got off in time before the secret clock expired.

How about in basketball, is there a secret clock that's real instead of the stadium clock?

---

[cardcrimson]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

That's a cover up for you. So the stadium clock is off, seriously? I guess we should assume the 25 (or 40) second clock is off as well. Soon we'll be having video replays to determine if a play got off in time before the secret clock expired.

How about in basketball, is there a secret clock that's real instead of the stadium clock?

---

[BostonCard]

(Very classy) Statement from the WMU President:

https://x.com/RyanHawk12/status/20967208...deo/1?s=61

Lots of good memes, and Mike Pereira makes the good point that in the NFL, that in cases where there is a discrepancy between the stadium clock and the refs clock, officials should defer to the clock that the public can see to avoid creating the appearance of impropriety.

https://x.com/sonnybunch/status/20969631...44154?s=61

That being said, if the BigTen had rigged the game, I’m impressed that they would have been able to do so in the minute or so between the end of the play and when the replay was loaded.

I like that in the college volleyball broadcasts, TV viewers see the exact feed that the refs see during the replay.

BC

---

https://x.com/thebabylonbee/status/20967...97259?s=61

Had to share that one…

BC

[BostonCard]

(Very classy) Statement from the WMU President:

https://x.com/RyanHawk12/status/20967208...deo/1?s=61

Lots of good memes, and Mike Pereira makes the good point that in the NFL, that in cases where there is a discrepancy between the stadium clock and the refs clock, officials should defer to the clock that the public can see to avoid creating the appearance of impropriety.

https://x.com/sonnybunch/status/20969631...44154?s=61

That being said, if the BigTen had rigged the game, I’m impressed that they would have been able to do so in the minute or so between the end of the play and when the replay was loaded.

I like that in the college volleyball broadcasts, TV viewers see the exact feed that the refs see during the replay.

BC

---

https://x.com/thebabylonbee/status/20967...97259?s=61

Had to share that one…

BC

[M T]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

This is an example of Segal's Law, "A man with a watch knows what time it is. A man with two watches is never sure."  (For the purists, Wikipedia notes that it predates the attribution to Segal, but that's the name it acquired.)

What a bunch of Bad Info is being spread, as best I can tell.  (For instance, here)

Ask yourself, what is this clock they talk about.  It isn't the game clock.  It isn't some electronic clock like your watch (which wouldn't come close to losing 1/30 of a second over 5 hours).  I believe it is the individual video frames as recorded in a separate file for each camera stream.  Each sequence of recorded frames is what they refer to as a clock. If a frame isn't received, that sequence may have gaps, which will show up, I believe, as lost ticks, so the "clock" runs fast.)  If one stream ia missing a frame, when you play it back, it ends earlier (ie, runs fast) than a stream that lost no frames.

Remember that all we see (and what the officials saw) are playbacks of the various camera feeds that have been stored somewhere.  Any of them could have gaps, causing any of them to end sooner than others.

(Ignore the broadcast's computer graphic of the time.  There can be all sorts of errors in that.  Instead only look at the recordings of the stadium clock (or the clock that controls them).)

I found a replay of the game.  In the "live" feed, NBC did not have the inset of the stadium clock.  Instead, NBC replayed a recording of that play and inserted a replay of the game clock.  This means that NBC could have errors in the synchronization of the replay of the stadium clock and the replay of the field, just like the Big Ten officials could have errors in their synchronization of the two as well.  (Had NBC shown the inset during the play, then I would have trusted their video more.  Now, I can't tell.)

BC, I think both feeds were showing one version or the other of the game clock. The officials might have recorded the stadium clock - it certainly has the same segments as the clock shown by NBC. Or maybe they showed a recording of the official's clock (in a booth somewhere) which controls the stadium clocks. The command to change the lights from 0:01 to 0:00 might hit the official's clock in a nanosecond (literally) while the same command to the stadium clocks would arrive a few microseconds later (accounting for setting up the command packet, sending it out, it being routed to the stadium clocks, speed of light to the stadium clocks, arrival of the packet, and interpretation of the packet). Since the cameras observe at likely no better than millisecond resolution (a frame is about 30 ms), the difference in arrival time should be a couple of orders of magnitude less than the temporal resolution of observing them. If Wifi is involved, then the delays could be considerably more but should still normally be less than 10 milliseconds.

But, yes, there could be a technical glitch that makes the two noticeably different, so a rule deferring to the stadium clock is reasonable.

Now that I think about it, the use of off-site replay officials seems to me to significantly increase the chances of lost frames (more networking infrastructure between camera and recording device). That won't matter much if individual views are separately used to make a call (did the tag touch the player) but it can matter if two cameras are coordinated (one camera on the bag at first base while the other is watching the ball go into the glove).

Again, tagging frames with the source's GPS time seems so simple and avoids most problems (that is, if you have GPS).

[M T]

Western Michigan has accepted the results and NBC has explained that its inset clock should not be taken as official.  I also found the realtime discussion amongst the refs as convincing, so I accept the explanation.  It is pretty egregious that in the year 2026 a major broadcast network is still displaying a clock off by ~ half a second, but that’s on NBC.  I think MT is correct that modern GPS technology should enable accurate time stamps of every frame to be embedded in the frame transmission.

Anyway, it’s 2026, and I am not surprised at all that a controversial game ending call has inspired a lot of conspiratorial thinking.  Add to the mix gambling and “prediction” markets (I wonder how much money was re-directed on account of the reversal) and it is a recipe for disaster.

BC

This is an example of Segal's Law, "A man with a watch knows what time it is. A man with two watches is never sure."  (For the purists, Wikipedia notes that it predates the attribution to Segal, but that's the name it acquired.)

What a bunch of Bad Info is being spread, as best I can tell.  (For instance, here)

Ask yourself, what is this clock they talk about.  It isn't the game clock.  It isn't some electronic clock like your watch (which wouldn't come close to losing 1/30 of a second over 5 hours).  I believe it is the individual video frames as recorded in a separate file for each camera stream.  Each sequence of recorded frames is what they refer to as a clock. If a frame isn't received, that sequence may have gaps, which will show up, I believe, as lost ticks, so the "clock" runs fast.)  If one stream ia missing a frame, when you play it back, it ends earlier (ie, runs fast) than a stream that lost no frames.

Remember that all we see (and what the officials saw) are playbacks of the various camera feeds that have been stored somewhere.  Any of them could have gaps, causing any of them to end sooner than others.

(Ignore the broadcast's computer graphic of the time.  There can be all sorts of errors in that.  Instead only look at the recordings of the stadium clock (or the clock that controls them).)

I found a replay of the game.  In the "live" feed, NBC did not have the inset of the stadium clock.  Instead, NBC replayed a recording of that play and inserted a replay of the game clock.  This means that NBC could have errors in the synchronization of the replay of the stadium clock and the replay of the field, just like the Big Ten officials could have errors in their synchronization of the two as well.  (Had NBC shown the inset during the play, then I would have trusted their video more.  Now, I can't tell.)

BC, I think both feeds were showing one version or the other of the game clock. The officials might have recorded the stadium clock - it certainly has the same segments as the clock shown by NBC. Or maybe they showed a recording of the official's clock (in a booth somewhere) which controls the stadium clocks. The command to change the lights from 0:01 to 0:00 might hit the official's clock in a nanosecond (literally) while the same command to the stadium clocks would arrive a few microseconds later (accounting for setting up the command packet, sending it out, it being routed to the stadium clocks, speed of light to the stadium clocks, arrival of the packet, and interpretation of the packet). Since the cameras observe at likely no better than millisecond resolution (a frame is about 30 ms), the difference in arrival time should be a couple of orders of magnitude less than the temporal resolution of observing them. If Wifi is involved, then the delays could be considerably more but should still normally be less than 10 milliseconds.

But, yes, there could be a technical glitch that makes the two noticeably different, so a rule deferring to the stadium clock is reasonable.

Now that I think about it, the use of off-site replay officials seems to me to significantly increase the chances of lost frames (more networking infrastructure between camera and recording device). That won't matter much if individual views are separately used to make a call (did the tag touch the player) but it can matter if two cameras are coordinated (one camera on the bag at first base while the other is watching the ball go into the glove).

Again, tagging frames with the source's GPS time seems so simple and avoids most problems (that is, if you have GPS).

[Goose]

BC, I think both feeds were showing one version or the other of the game clock.  The officials might have recorded the stadium clock - it certainly has the same segments as the clock shown by NBC.  Or maybe they showed a recording of the official's clock (in a booth somewhere) which controls the stadium clocks. The command to change the lights from 0:01 to 0:00 might hit the official's clock in a nanosecond (literally) while the same command to the stadium clocks would arrive a few microseconds later (accounting for setting up the command packet, sending it out, it being routed to the stadium clocks, speed of light to the stadium clocks, arrival of the packet, and interpretation of the packet).  Since the cameras observe at likely no better than millisecond resolution (a frame is about 30 ms), the difference in arrival time should be a couple of orders of magnitude less than the temporal resolution of observing them.    If Wifi is involved, then the delays could be considerably more but should still normally be less than 10 milliseconds.

But, yes, there could be a technical glitch that makes the two noticeably different, so a rule deferring to the stadium clock is reasonable.

Now that I think about it, the use of off-site replay officials seems to me to significantly increase the chances of lost frames (more networking infrastructure between camera and recording device).  That won't matter much if individual views are separately used to make a call (did the tag touch the player) but it can matter if two cameras are coordinated (one camera on the bag at first base while the other is watching the ball go into the glove).

Again, tagging frames with the source's GPS time seems so simple and avoids most problems (that is, if you have GPS).

First, the frame rate of modern "TV" is 60 frames per second, not 30 frames per second. Each frame is 16.666... ms long. Second, in stadiums the cameras are all "GenLocked" together. Each frame on all cameras starts at almost exactly the same time. There is less than a millisecond delta between them.
 
There are exceptions in the case of some highly mobile cameras but they are few. Ask Google the following question: "are the skycams genlocked to the same reference as other cameras in the stadium". The answer is that indeed they are. The answer also contains an explanation of exactly how. It must be said that the critical concept is that all frames of essentially all cameras in the stadium start at almost exactly the same time. The reason for this is historical. Before digital technology was available if a switch was made from one analog video stream (camera) to another and said frames were not in sync the analog TVs watching the game would lose vertical sync. If each line of the frame wasn't started at the correct time the TVs would loose horizontal sync. You would get a "video tear" and lose several frames before the customer's TVs would re-lock. Obviously customers wouldn't like that. Therefore the system was designed to ensure that wouldn't happen.

In a modern digital system it is possible to buffer up frames and delay transmitting them. That allows fixing framing errors from the few cameras that are not genlocked to the master. If frames are "lost" in the digital transmission system the receiving system knows it because the UDP IP packet sequence numbers contain a "hole". If TCP is used retransmission will ensure nothing is lost. The problem with TCP is that retransmission may take too long and a frame may be unavailable when it is needed to be displayed. This isn't a problem in a replay situation because the replay can be buffered as much as necessary to ensure no packets are missed. In "real time" displays what is displayed when a necessary packet is not available is usually the previous packet. OK visually if only a few packets are lost, not so good otherwise. I think we have all seen this when serious technical difficulties exist. The actual transmission to the customer of the video data is always buffered considerably. This allows TCP data to be re-transmitted without being visually noticeable.

Given that the cameras are genlocked and the frames are of a fixed temporal length the time of each frame can be determined to at least ms accuracy simply by counting frames (including missed frames if any by noting packet sequence number gaps). You can use a Stratum 0 reference if you wish, but it isn't necessary. A good TCXO will work just fine. All the timing is relative to the same reference. The drift of the reference is much much less than other errors in the system.
 
The TV technology is not the issue. If there is a camera genlocked to the same master recording the displayed game time the game timestamp of each individual frame can be very precisely determined. What NBC and/or the NCAA/B1G deploys to execute this determination is another question. A system that automates displaying the game time for each frame can relatively easily be constructed using the existing hardware design. Whether that has been done or not I don't know.

[Goose]

BC, I think both feeds were showing one version or the other of the game clock.  The officials might have recorded the stadium clock - it certainly has the same segments as the clock shown by NBC.  Or maybe they showed a recording of the official's clock (in a booth somewhere) which controls the stadium clocks. The command to change the lights from 0:01 to 0:00 might hit the official's clock in a nanosecond (literally) while the same command to the stadium clocks would arrive a few microseconds later (accounting for setting up the command packet, sending it out, it being routed to the stadium clocks, speed of light to the stadium clocks, arrival of the packet, and interpretation of the packet).  Since the cameras observe at likely no better than millisecond resolution (a frame is about 30 ms), the difference in arrival time should be a couple of orders of magnitude less than the temporal resolution of observing them.    If Wifi is involved, then the delays could be considerably more but should still normally be less than 10 milliseconds.

But, yes, there could be a technical glitch that makes the two noticeably different, so a rule deferring to the stadium clock is reasonable.

Now that I think about it, the use of off-site replay officials seems to me to significantly increase the chances of lost frames (more networking infrastructure between camera and recording device).  That won't matter much if individual views are separately used to make a call (did the tag touch the player) but it can matter if two cameras are coordinated (one camera on the bag at first base while the other is watching the ball go into the glove).

Again, tagging frames with the source's GPS time seems so simple and avoids most problems (that is, if you have GPS).

First, the frame rate of modern "TV" is 60 frames per second, not 30 frames per second. Each frame is 16.666... ms long. Second, in stadiums the cameras are all "GenLocked" together. Each frame on all cameras starts at almost exactly the same time. There is less than a millisecond delta between them.
 
There are exceptions in the case of some highly mobile cameras but they are few. Ask Google the following question: "are the skycams genlocked to the same reference as other cameras in the stadium". The answer is that indeed they are. The answer also contains an explanation of exactly how. It must be said that the critical concept is that all frames of essentially all cameras in the stadium start at almost exactly the same time. The reason for this is historical. Before digital technology was available if a switch was made from one analog video stream (camera) to another and said frames were not in sync the analog TVs watching the game would lose vertical sync. If each line of the frame wasn't started at the correct time the TVs would loose horizontal sync. You would get a "video tear" and lose several frames before the customer's TVs would re-lock. Obviously customers wouldn't like that. Therefore the system was designed to ensure that wouldn't happen.

In a modern digital system it is possible to buffer up frames and delay transmitting them. That allows fixing framing errors from the few cameras that are not genlocked to the master. If frames are "lost" in the digital transmission system the receiving system knows it because the UDP IP packet sequence numbers contain a "hole". If TCP is used retransmission will ensure nothing is lost. The problem with TCP is that retransmission may take too long and a frame may be unavailable when it is needed to be displayed. This isn't a problem in a replay situation because the replay can be buffered as much as necessary to ensure no packets are missed. In "real time" displays what is displayed when a necessary packet is not available is usually the previous packet. OK visually if only a few packets are lost, not so good otherwise. I think we have all seen this when serious technical difficulties exist. The actual transmission to the customer of the video data is always buffered considerably. This allows TCP data to be re-transmitted without being visually noticeable.

Given that the cameras are genlocked and the frames are of a fixed temporal length the time of each frame can be determined to at least ms accuracy simply by counting frames (including missed frames if any by noting packet sequence number gaps). You can use a Stratum 0 reference if you wish, but it isn't necessary. A good TCXO will work just fine. All the timing is relative to the same reference. The drift of the reference is much much less than other errors in the system.
 
The TV technology is not the issue. If there is a camera genlocked to the same master recording the displayed game time the game timestamp of each individual frame can be very precisely determined. What NBC and/or the NCAA/B1G deploys to execute this determination is another question. A system that automates displaying the game time for each frame can relatively easily be constructed using the existing hardware design. Whether that has been done or not I don't know.

[newguy]

i'm about 50/50 on whether or not they got it right.  but i still say that all major conferences should do what the ACC did in our game.......show the video and audio inside the replay booth.

transparency inspires confidence.

[newguy]

i'm about 50/50 on whether or not they got it right.  but i still say that all major conferences should do what the ACC did in our game.......show the video and audio inside the replay booth.

transparency inspires confidence.

[BostonCard]

A penny for Phogge’s thoughts.

BC

[BostonCard]

A penny for Phogge’s thoughts.

BC

[Spiny_Norman]

There is a Stanford angle to this game. Western Michigan's head coach is Lance Taylor. He was RB coach at Stanford for 2014-2016 which means that he was Christian McCaffrey's (and Bryce Love's) position coach.

[Spiny_Norman]

There is a Stanford angle to this game. Western Michigan's head coach is Lance Taylor. He was RB coach at Stanford for 2014-2016 which means that he was Christian McCaffrey's (and Bryce Love's) position coach.

[ADPinWDC]

I'm pretty sure if the roles were reversed the WMU would not have gotten a second chance at a Hail Mary......

Totally Agree.  Homer call of the Decade.  Broncos got their gate receipts (a hefty $1.5M, plus 400 tickets), 
and free bus fare (105 miles) back to Western Michigan in Kalamazoo.
B1G Aristocrats called the booth -- said, "Save our TV revenues; give Wolvs another shot. Whittingham's DEBUT!!"  
It looked like a remake of the Mens' basketball gold medal game vs USSR in 1972.
MICH favored by 27.5 ... and they barely score 13, nay, 7 points. No shame in Ann Arbor. Travesty.

"Biggest Robbery" !
https://www.youtube.com/shorts/p3AbQcYl69Y

MICH plummets 8 spots from #16 to #24 in today's NCAA poll.
https://sports.yahoo.com/articles/michig...02670.html?

[ADPinWDC]

I'm pretty sure if the roles were reversed the WMU would not have gotten a second chance at a Hail Mary......

Totally Agree.  Homer call of the Decade.  Broncos got their gate receipts (a hefty $1.5M, plus 400 tickets), 
and free bus fare (105 miles) back to Western Michigan in Kalamazoo.
B1G Aristocrats called the booth -- said, "Save our TV revenues; give Wolvs another shot. Whittingham's DEBUT!!"  
It looked like a remake of the Mens' basketball gold medal game vs USSR in 1972.
MICH favored by 27.5 ... and they barely score 13, nay, 7 points. No shame in Ann Arbor. Travesty.

"Biggest Robbery" !
https://www.youtube.com/shorts/p3AbQcYl69Y

MICH plummets 8 spots from #16 to #24 in today's NCAA poll.
https://sports.yahoo.com/articles/michig...02670.html?

[Bruce Wang]

The Meatchicken Skunkbears would be better off taking the L than suffer the ignominy of memes like this.

   

[Bruce Wang]

The Meatchicken Skunkbears would be better off taking the L than suffer the ignominy of memes like this.

   

[M T]

MAC appeals Michigan-Western Michigan result, asks NCAA and CFP to recognize Broncos as winner

In his letter to the FBS Oversight Committee, MAC Commissioner Jon Steinbrecher said “established protocol” in this situation is that the television truck is contacted with a request to insert the in-stadium game clock onto “the program feed” — and that is supposed be the sole source of the replay decision.

[M T]

MAC appeals Michigan-Western Michigan result, asks NCAA and CFP to recognize Broncos as winner

In his letter to the FBS Oversight Committee, MAC Commissioner Jon Steinbrecher said “established protocol” in this situation is that the television truck is contacted with a request to insert the in-stadium game clock onto “the program feed” — and that is supposed be the sole source of the replay decision.