The Oakland A’s lead the American League in a non-trivial offensive category. They swing at the fewest pitches of any other team. That might not seem like a huge surprise; after all, Moneyball is loaded with anecdotes that convey the A’s stance on plate discipline. Yet they haven’t turned that discipline into results. Their 92 wRC+ ranks 11th in the AL, and their 8.3 percent walk rate ranks only fifth. The results raise the question of whether the A’s are actually disciplined. Could they actually be merely passive?
Unsurprisingly, the evidence points towards passivity. It’s not as though Oakland hitters lay off only the bad pitches and swing at the good ones. While they have swung at the fewest pitches outside the strike zone, just 25.6 percent, they also have swung at the second fewest percentage of pitches within the strike zone. At the same time, they’re fed more pitches inside the strike zone than any other team. It comes as even less of a surprise, then, that they have the highest percentage of looking strikes in the league. They simply do not swing the bat as frequently as other teams.
The Yankees have the second lowest swing rate in the league, but they’re not nearly as passive as the A’s. They swing at more pitches within the zone than the A’s, they draw more walks, and they see more pitches per plate appearance. At the same time, they see the fewer pitches in the zone than any other team in the AL. On one hand, then, the A’s see more strikes than anyone and they swing at the fewest pitches, while the Yankees see the fewest pitches in the zone and they swing at the second fewest pitches. It doesn’t take much more than that to illustrate the differences between discipline and passivity.
Here’s another difference between the Yankees and the A’s. The Yankees lead the league in 3-1 counts, having seen them in 11 percent of all plate appearances. The A’s have seen 3-1 counts in 9 percent of their PA, which is right around the league average. The Yankees also lead the league in 2-0 counts seen, while the A’s are 13th. What’s the point of taking so many pitches if you’re not eventually working yourself into a better count? It’s hard to do, though, when pitchers simply feed you more strikes. That means more looking strikes, which leads to worse hitters’ counts.
There is no one stat that defines plate discipline. All we can do is look at a number of stats that relate to the concept and try to grade teams. When looking at overall swing rate and out of zone swing rate, it might seem as though the A’s are one of the most disciplined teams in the league. But when we dig a bit deeper, we see that they simply don’t swing the bat. The Yankees, on the other hand, swing infrequently because they’re fed fewer strikes than any other team. They for the most part lay off pitches outside the zone, they work favorable hitters’ counts, and they take their walks. It’s something we’ve seen them do for decades now, but it will never get old.