More on Called Strikes on the Edge

When we last left our discussion of Edge% we were looking at the differences in the rate of called strikes based on the count. Generally speaking, umpires were less likely to call strikes on the Edge in pitcher-friendly counts and more likely to give those calls in hitter-friendly counts.

While we learned a bit from that analysis, it was really just the tip of the iceberg. There are a number of additional ways to cut the data, and that is the focus of this article. Count is just one dimension when we are thinking about what might influence the likelihood of close called strikes. There are a number of additional dimensions we can layer onto count, and that’s precisely what I show in the (admittedly large) table below.

The data below represents the called strike percentage on taken pitches thrown to the Edge at the league level, cut by count as well as other “splits”, including: pitch type, type of platoon matchup, pitcher and batter handedness, and inning. Like the previous article, the numbers here include pitches thrown between April 1 and July 10 of this year.

Readers will notice that I’ve also included the overall league average for each count for reference.

A few clarifications before we dive in. First, pitch type should be pretty straightforward as I am simply using the standard PITCHf/x classifications. Platoon simply refers to any situation where the pitcher and batter are of the opposite handedness (e.g. RHP vs. LHB). I also have included each platoon situation broken out individually. The rest should be self-explanatory — RHP includes only pitches taken on the edge by count thrown by righties, etc. Finally, I included splits by inning. Obviously the numbers get pretty small pretty fast once you get past the ninth inning, but there was no harm in including the data.

On to the data.

The first thing I wanted to see was whether any splits displayed a significantly different pattern from the prior analysis — meaning, the percent of called strikes increases as the count moves away from the pitcher’s favor.

For splits with greater than 5000 pitches taken on the Edge there were only two true outliers in terms of 3-0 counts — split-finger fastballs and sliders. Splitters taken on the Edge are called strikes less than 1% of the time in 3-0 counts, while sliders had a called strike rate of 65%. For all counts, that >1% ranked dead last for splitters, while the 65% for sliders ranked seventh. For reference, 3-0 counts generate the highest called strike percentage on the Edge on average at a league-level.

Otherwise, the pattern by count seemed pretty consistent by pitch type. The same holds true for handedness match-ups and innings (at least through the 9th).

But while the overall pattern by split was consistent, there were certainly some differences in terms of the relative called strike percentage by count, by split.

For example, 0-2 counts are the hardest for pitchers to get called strikes on the Edge (53% on average). But change ups make it even harder, notching a 38% called strike rate on 0-2. That’s by far the lowest rate of any split in that count examined here. However, change ups are even more advantageous on 3-0 than league average, getting the call 88% of the time (9% higher than league average).

The best pitch to throw on the Edge on 3-0? That would be a curveball, which gets the call 100% of the time (24% above league average).

And if you are looking to get a punch out in any two-strike count on the Edge it’s best to stick with your fastball, particularly cutters (9% above league), two-seamers (also 9% above league), and sinkers (15% above league, best of any pitch type).

How about handedness splits?

This is where some of the most interesting patterns emerged for me. Let’s first compare all platoon situations against same-handedness situations.

Overall, there isn’t much difference in the overall Edge called strike rates for either split (>1% of difference). However, pitchers in platoon situations are able to get Edge strike calls at a higher rate on more pitcher-friendly counts, such as 0-2, 1-2, and 2-2 (leading to their 5% advantage in all two-strike counts). This advantage reverses once we look at batter-friendly counts, where same handedness seems to give pitchers a bit better advantage.

There is also a clear difference in the type of platoon match-up that is best for getting Edge calls — RHB against LHP.

Overall, RHB/LHP gives pitchers a 6% advantage on Edge calls versus the opposite matchup. And the advantage seems to hold throughout just about every count. When facing RHB, lefties manage Edge called strike rates of 68% and 77% in 2-2 and 1-1 counts, respectively. That’s good for a 7% and 11% advantage relative to the opposite matchup, but more importantly those numbers are 13% better than league average in both those crucial counts.

To wrap up, I was somewhat expecting that as the game wore on there would be an increase in Edge called strike rate. In terms of the first nine innings, the overall rate is pretty darn stable — fluctuating between 68% and 71%. And as we enter extra innings those rates actually decline — pretty drastically, in fact — rather than increase. Of course, the sample size here gets pretty small, but at first glance pitchers appear to get squeezed more in extra innings overall.

At this point, I don’t have any definitive plans of where to go next, so feel free to offer up some suggestions in the comments.