Taking a break from looking at batting results, I wanted to take a quick look at another subject that has been very important in recent Pitch F/X research, pitch sequencing.
I think a good way to start is to approach sequencing the same way I did, looking to at-bats that contained both a whiff and a home run, meaning that the pitcher was able to make the batter swing and miss on one pitch, only to give up a home run later in the at-bat. There were 6 such at-bats in the AFL Pitch F/X games:
The Peter O'Brien/Dominic Leone at-bat is fascinating because Leone managed to get O'Brien to swing and miss at two different pitches, one out of the zone and one in the zone, and then threw a third separate pitch in the strike zone, in a different part of the strike zone, and it was hit for a homer. Here is a location graph showing the three pitches:
Of course, the at-bat actually lasted 8 pitches, so the three pitches above were just a small, though dramatic part, of the battle at the plate. Here are where all 8 pitches were located, labelled with the MLBAM tags of the pitches, along with the amount of strikes there were at the time the pitch was thrown:
Of course, we want to look at larger sample sizes, and look at more results than just home run at-bats that also contained whiffs. So here we will take a look at strikeout at-bats, breaking them down by what pitches were thrown by the amount of strikes in the count.
Here are all the pitches in Arizona Fall League Pitch F/X games in 2013 that were either called a strike or swung and missed at in at-bats that ended with a strikeout. First, here are the pitches that were thrown with no strikes:
With 1 strike:
With 2 strikes:
In case the graphs do not show it, here are the average locations in strikeout at-bats, broken down by how many strikes there were at the time the pitch was thrown:
Not surprisingly, when pitchers in the AFL got to two strikes, they tended to throw more breaking balls, which are lower in the zone on average. Surprisingly, there isn't much of a difference in horizontal location.