Comparing Plate Discipline: Visually and Numerically

Here at Fanpraphs, we have plate discipline recorded for each hitter going back to 2002. These values are useful, but how do these values translate into the exact strike zone that a players uses? Today, I decided to look at how the visual and numerical plate discipline compares for three players, Brett Gardner, Vladimir Guerrero, and Torii Hunter.

I chose these three players because they each had varying degrees of plate discipline according to their Swing% (Total percentage of pitches a batter swings at). Out of all qualified batters in 2010, Brett had the lowest Swing% while Vlad had the highest. I also wanted to have a player with an average Swing%, and Torii was picked. Here is a chart of their 2010 Swing% values:

Now, here is how each of the three players swung at pitches during the 2010 season:

The scale equals the number of pitches swung at (contact or no contact) divided by all pitches thrown in that part of the plate. I am looking at 6” square boxes and have a zone for both left handed and right handed pitchers. The view is from the catcher’s perspective looking at the pitcher. The box is the MLB regulation strike zone and the circle is used just for reference.

Brett Gardner (Swing% = 31.0%)
vs. Left Handed Pitcher

vs. Right Handed Pitcher

Torii Hunter (Swing% = 46.5%)
vs. Left Handed Pitcher

vs. Right Handed Pitcher

Vladimir Guerrero (Swing% = 60.6%)
vs. Left Handed Pitcher

vs. Right Handed Pitcher

The visuals nicely back up the numbers. For pitches in heart of the strike zone, Brett rarely swings at any pitch over 60% of the time. Vlad on the other hand is swinging at pitches over 90% of the time depending on the pitch’s location. Finally Torii seems to have a nice understanding of the strike zone.

For comparison sake, here is each player’s personal strike zone dating back to 2007:

Brett Gardner
vs. Left Handed Pitcher

vs. Right Handed Pitcher

Torii Hunter
vs. Left Handed Pitcher

vs. Right Handed Pitcher

Vladimir Guerrero
vs. Left Handed Pitcher

vs. Right Handed Pitcher

I hope having the visual zone to go with the numerical zone will give you a better perspective of a player’s strike zone. I will be doing more of these comparisons in the future, so let me know if you have any questions.