Plate discipline, like basically everything in baseball, is not merely a black-and-white concept. Much like cake, ogres, and the feudal system of the medieval era, it has layers to it. Too often, we see plate discipline translated simply into patience. That is, of course, one facet of it. Even that, though, operates heavily in shades of gray.
Baseball at any level has this long-held belief that a player who sees a high volume of pitches is automatically a better producer of offense than someone who presents as aggressive at the plate. At the highest level, we know that this isn’t necessarily always true (the amateur levels still have some work to do there).
For example, someone like Trent Grisham could be characterized as being too patient. While routinely sitting among the league’s lowest swing rates, he works himself into deep counts on a constant basis. He’s also without the contact ability to compensate when he’s at 2-2 or 3-2. Conversely, Luis Arraez — who may very well be the best pure hitter the game has to offer — isn’t anywhere near the top of the leaderboard in swing rate or pitches per plate appearance (P/PA). Surely we don’t think less of him because he doesn’t see a high volume of pitches.
There are myriad ways in which we can quantify plate discipline. A low swing rate. A high pitchers-per-plate appearance. Minimizing chase percentage. A high swing percentage inside of the strike zone. Even a high contact rate, regardless of swing rates, can be representative of quality plate discipline. For my purposes here, however, the patience aspect is of the greatest interest.
on the Wall in the Box
Patience mainly hones in on two components of plate discipline: Swing% & P/PA.
Here are the five lowest swing rates in baseball thus far:
And here are the five highest P/PA: