Which Pitchers are Really Getting Squeezed?

Earlier in the week we took a look at which pitchers have been squeezed the most based on total pitches called balls within the PitchFX established strike zone.  While it appeared that pitchers like C.J. Wilson (TEX) and Jon Niese (NYM) have been getting a tight strike zone, the truth is that these pitchers tend to stay around the strikezone with the majority of their pitches.  In fact, C.J. Wilson leads the league in called strikes within the strike zone:

(Data from all 2011 games through May 10th)

So in reality, while pitchers like Wilson do lose a lot of called strikes on the borders, it's mostly a product of the volume of pitches they locate there.  In fact, through Tuesday, Wilson was leading all pitchers in total called strikes, regardless of location, with 194.

If we really want to see which pitchers have had a tough time getting calls from umps, we need to look at the percentage of called strikes out of all taken pitches within the strike zone.

 (Data from all 2011 games through May 10th - Min. 40 taken pitches in the strike zone)

Wilson still cracks the top 50, but he's far from the most squeezed pitcher in the league.  Mariners' closer Brandon League is not getting the majority of close calls so far this season.  The league average for called strikes in the PitchFX defined strike zone has been around 77%, meaning umpires have called 23% of pitches in the zone balls.  Of course, the majority of these are borderline pitches as the following graphic shows:

All MLB Called Balls in Strike Zone (Click to enlarge)

League's missed strikes consist of 18 pitches, the majority of which were thrown to the bottom of the zone.  Batters have taken only 42 total strike zone pitches against him, so his "squeeze rate" is mostly a product of small sample size.  However, when we filter the list down to starters....

(Data from all 2011 games through May 10th)

Among starters, Wilson and Niese still near the top of the list of pitchers getting squeezed. And perhaps Nelson Figueroa would still be pitching in Houston if we had robot umpires.

So we've seen which pitchers have not gotten the majority of close calls so far this season.  In an upcoming post, we'll look at pitchers that have benefited most from expanded strike zones.

Comments

If you look at the raw pitch location data, it doesn't show this pattern. I'm convinced that the normalization using sz_top and sz_bot values from PITCHf/x operator are causing the bulk of this effect, rather than any real difference in umpire calls. The fact that the big differences show up along the bottom border of the zone is an indicator of that. The sz_bot values in the data are not good, and small sample sizes with relief pitchers are going to be very sensitive to that.