Certainly not debating the time between pitches (although this data was for two specific games, so it is a bit of a small sample and could be attributed to the specific pitchers/hitters in the 2014 game), but one thing I have been wondering is how the number of foul balls in today's game compares to the number of foul balls from years ago. It seems like, and I have no data to prove this, there are a lot more foul balls now because of better pitching and less concern about strikeouts. Foul balls take up a lot of time (fielders chasing if they are close to or in the field of play, getting the ball back to the pitcher, getting balls to the ump if he is out, etc.), much more so than the return of an inaction pitch, and result in longer at-bats. Also, anecdotally, stadiums have reduced foul territory to get fans closer to the field (and thus increase those seat prices), which would suggest more foul balls out of play and not caught, resulting in longer at-bats.