So far this week, we’ve spent a good deal of time talking about Jacob Peterson’s super special awesome new plate discipline statistics. We’ve used his innovative approach to measure each Indians hitter’s “Passiveness” and “Aggressiveness,” and today we put it all together with what Peterson calls “Passive-Aggressiveness”—a stat that can tell us a great deal about a batter’s ability to control the strike zone.
This composite stat is simply a player’s Passiveness and Aggressiveness scores added together (for more on what those mean and how they’re calculated, check out Peterson’s original post). In other words, it’s the number of called strikes and chased would-be balls a batter takes or swings at per 100 pitches. Or: the proportion of pitches for which the batter does not make the expected decision about whether or not to swing.
Before we dig into the numbers, I think that last point needs further explaining. In reality, unlike in these data, the distinction is not so clear-cut as in these numbers. If a hitter knows he can’t do much with a pitch on the corner it’s worth taking the strike, and if he can mash a hanging pitch a little off the plate he shouldn’t watch it go by just because the umpire would call it a ball. Though they sound like inherent negatives, taking called strikes and (to a lesser extent) swinging at pitches off the plate aren’t necessarily bad. Therefore, these numbers could be better described as measuring the ability to control and judge the strike zone than plate discipline. It’s a fine distinction, but solid analyses cannot be founded on misinterpreted data.
Without further ado, here are the Passive-Aggressive scores for each of the 2011 Tribe position players. These numbers may differ from Peterson’s, as these data come from FanGraphs while he used statistics from Baseball Prospectus.
With some notable exceptions, this list reads pretty much like a list of players arranged in ascending order of hitting ability. As Peterson pointed out, this makes a good deal of sense—pitch recognition is a pretty important skill for a hitter to have—but it’s still a strong reminder of the importance of plate discipline.
This is especially noticeable at the top of the list: Shelley Duncan excepted, the top six looks like a group of the most disappointing hitters of the year. It’s worth noting that Matt LaPorta ranks very differently here than he did on Peterson’s list, where he came out as one of the least Passive-Aggressive hitters in baseball—that’s the importance of discrepancies in the data. Tellingly, only one (Jason Donald) of the top 10 managed an above-average wRC+.
The middle ranks are full of interesting names. Trevor Crowe and Jerad Head didn’t get enough playing time for us to make anything close to sweeping conclusions. Asdrubal Cabrera had a very good season, and Jason Kipnis was torrid in his 150 MLB plate appearances. That Grady Sizemore rose this high is telling, as it fits in well with the observable decline in his plate discipline.
Finally, the bottom of the list is about what we should have expected. Jack Hannahan, Austin Kearns, and Michael Brantley quietly demonstrated solid patience. Travis Hafner, Carlos Santana, and Jim Thome are no surprises. The name that really stands out for me is Lou Marson—clearly plate discipline isn’t his problem.
Take these numbers with a grain of salt; LaPorta’s case illustrates that the data are questionable, and it’s hard to describe what exactly the numbers mean. But they still tell an interesting story about how Indians players approach the art of hitting.