[BostonCard]

Someone can correct my math on this but I'm tempted to look at the 2nd down numbers and conclude that with 9+ ypa and only 36% 1st downs that our first down play is either incomplete or getting stuffed about 64% of the time.  And I'm not surprised if that indeed is true.

That's not right.  Let's say that our first down plays always result in either a first down or a second a five.  If our second down throws are complete for 27 yards 1/3 of the time, and incomplete 2/3 of the time, we would average 9 ypa, but only 33% 1st downs.  You can't make any conclusions about what happened on first down.

What we do know, is that on second down passes, we gain a first down 33% of the time and a touchdown 11% of the time (43 first downs and 11 touchdowns in 130 passes), we threw an incompletion or interception 35% of the time (since the completion percentage is 65%), which leaves 21% of the time where we throw a completion short of the sticks.  The average yards per completion is about 12.7 yards (1080 total yards/85 completions), but of course the first down percentage will depend on how many "to go" yards are needed and the variance around that average completion yardage.

Also, of note, this is only the throws on second down.  Typically the "to go" distance on second down is going to be greater for attempted passes than attempted runs.  We still passed on second down only 45% of the time (130 passes versus 156 rushes), and  got a first down or touchdown 33% of the time rushing on second down (40 first downs, 12 TDs in 156 rushes), gaining an average of 6.26 ypc.

BC

[BostonCard]

Someone can correct my math on this but I'm tempted to look at the 2nd down numbers and conclude that with 9+ ypa and only 36% 1st downs that our first down play is either incomplete or getting stuffed about 64% of the time.  And I'm not surprised if that indeed is true.

That's not right.  Let's say that our first down plays always result in either a first down or a second a five.  If our second down throws are complete for 27 yards 1/3 of the time, and incomplete 2/3 of the time, we would average 9 ypa, but only 33% 1st downs.  You can't make any conclusions about what happened on first down.

What we do know, is that on second down passes, we gain a first down 33% of the time and a touchdown 11% of the time (43 first downs and 11 touchdowns in 130 passes), we threw an incompletion or interception 35% of the time (since the completion percentage is 65%), which leaves 21% of the time where we throw a completion short of the sticks.  The average yards per completion is about 12.7 yards (1080 total yards/85 completions), but of course the first down percentage will depend on how many "to go" yards are needed and the variance around that average completion yardage.

Also, of note, this is only the throws on second down.  Typically the "to go" distance on second down is going to be greater for attempted passes than attempted runs.  We still passed on second down only 45% of the time (130 passes versus 156 rushes), and  got a first down or touchdown 33% of the time rushing on second down (40 first downs, 12 TDs in 156 rushes), gaining an average of 6.26 ypc.

BC