[Goose]

I think the logic is that a walk gets the runner to first base 100% of the time, but a ball hit into play will result in an out ~70% of the time (a typical batting average of balls hit into play is .300).  However, the way Lex phrased it is wrong; a single and walk are close to equivalent (not quite, because a walk will only advance a runner who can be forced to advance one base, while a single will almost always advance a runner, and can advance a runner more than one base).  The issue is that when you put the ball in play, you cannot guarantee a single.  On the other hand, a typical plate appearance will draw around 4 pitches, while the minimum pitch count for a walk is 4, so under the theory that getting the pitcher to pitch more pitches is good, a walk has that advantage over a single.

BC

A walk does have advantages over a single in many cases because it makes the pitcher throw more pitches. However, waiting for a walk results in lots of called third strikes. You don't get a walk on demand. I think it is axiomatic that you don't swing at pitches that are out of the strike zone. If they walk you, great. If the count involves 2 strikes, you have to be real sure the pitch is a ball if you chose not to swing at it.
With the shift, the probability of reaching base safely will go WAY up from less than 0.3 if you can slap the ball into the open side of the field. A guy like Carew could hit 0.950 against such a defense. If you are in a situation where strike 3 is coming (so you have to swing at it), going to the open side of the infield should be the obvious strategy. This is independent of any other "strategic" considerations. You can either 1) get on base with very high probability by hitting to the open side of the field, 2) drive the ball into the teeth of the defense (if you are lucky), or 3) take a called third strike. Choice seams clear to me.

[Goose]

I think the logic is that a walk gets the runner to first base 100% of the time, but a ball hit into play will result in an out ~70% of the time (a typical batting average of balls hit into play is .300).  However, the way Lex phrased it is wrong; a single and walk are close to equivalent (not quite, because a walk will only advance a runner who can be forced to advance one base, while a single will almost always advance a runner, and can advance a runner more than one base).  The issue is that when you put the ball in play, you cannot guarantee a single.  On the other hand, a typical plate appearance will draw around 4 pitches, while the minimum pitch count for a walk is 4, so under the theory that getting the pitcher to pitch more pitches is good, a walk has that advantage over a single.

BC

A walk does have advantages over a single in many cases because it makes the pitcher throw more pitches. However, waiting for a walk results in lots of called third strikes. You don't get a walk on demand. I think it is axiomatic that you don't swing at pitches that are out of the strike zone. If they walk you, great. If the count involves 2 strikes, you have to be real sure the pitch is a ball if you chose not to swing at it.
With the shift, the probability of reaching base safely will go WAY up from less than 0.3 if you can slap the ball into the open side of the field. A guy like Carew could hit 0.950 against such a defense. If you are in a situation where strike 3 is coming (so you have to swing at it), going to the open side of the infield should be the obvious strategy. This is independent of any other "strategic" considerations. You can either 1) get on base with very high probability by hitting to the open side of the field, 2) drive the ball into the teeth of the defense (if you are lucky), or 3) take a called third strike. Choice seams clear to me.