Pitcher and Position Use Surprise

In thinking about the Tampa Bays Rays and the use of the opener, I’m concerned about a tend that I assumed was happening in baseball. It was my belief that larger pitching staffs were cutting into position player use. In order to carry 12 and 13 man bullpens, managers had to give up some offensive flexibility. The use of an opener would, in my mind, would exacerbate that trend, since teams would be using more pitchers per game with the strategy.

I was surprised to be wrong on both counts. First, the Rays used 4.41 pitchers per game this season. That tied with the Braves for 12th most pitchers used per game this season, and 5th in the American League. The MLB average was 4.36 pitchers per game, so the Rays use of the opener did not make their overall use of pitchers that different than the average team.

The second thing I found was that use of non-pitchers in games has declined, but not my much. This spreadsheet charts MLB pitchers used per team game and MLB non-pitchers used per team game (PTG) over the last 40 seasons. In 1979, teams used 2.52 pitchers per team game, 10.62 non-pitchers PTG. In 2018, pitcher use had risen to 4.36 PTG, while non-pitchers had fallen to 10.37 PTG. For the regression lines, the slope for pitchers per season is 0.045, while the slope for non-pitchers comes in at -0.014.

Non-pitcher use did bounce up to a high of 10.92 in 1984, but in general it looks like there is about one less substitution every other team game compared to the 1980s. I suspect that teams discovered that they really weren’t using that many position players, which allowed them to keep expanding the bullpens. Teams are now just slightly more judicious in their use of substitutes.

Pitcher use rose fairly steadily until 2007, and then we saw an eight-year stabilization. In 2015, pitcher use rose above 4.0 PTG for the first time, and has risen every year since. The 2014-2015 seasons allowed the Royals to demonstrate to baseball what a three-closer bullpen could do on the game’s biggest stage. That was not lost on the rest of the majors, and we back on a trajectory of more pitchers every game.

from baseballmusings.com https://ift.tt/2OZNUEA