No Evidence Exists Showing "Three-Batter Minimum" Rule Will Lead To Quicker Games

Beginning with the 2020 season, Rule 5.10(g) will state that both starting and relief pitchers are required to pitch to either a minimum of three batters or to the end of a half-inning, with exceptions only for injury or illness. Commissioner Rob Manfred claims that this change will decrease the average time per game.

Opinions on this new rule run the gamut, from "no big deal" (Anthony Castrovince, mlb.com) to "a huge mistake" (Tom Verducci, Sports Illustrated) to "it will barely matter" (Ben Clemens, FanGraphs) to "it will have a significant effect" (Matt Provenzano, Beyond The Box Score).

I am completely against this rule. Even the fact that it was proposed in the first place is troubling. Also of concern is that Manfred sees no downside to altering 150 years of professional baseball by denying teams the right to change pitchers when they feel it is appropriate. ... I cannot wait until a team loses the World Series because they were forced to keep an ineffective pitcher in the game. (Actually, "I cannot wait" only if that team is the Yankees. (Which would undoubtedly lead to the abolition of the rule.))

The very thing Manfred wants to eliminate - relievers facing only one or two batters - has actually been decreasing in recent seasons. Tom Verducci of Sports Illustrated reported that pitchers in 2018 faced one or two batters mid-inning only 0.58 times per game: "For the sake of taking away one pitching change every other game, MLB [has] messed with the integrity of the game by penalizing strategy and innovation."

Thanks to Baseball Reference's Play Index, I was able to see how many relief appearances lasted one or two batters. (I did not determine how many of these appearances ended an inning, however.) I also looked at the average time of game (overall and for nine-inning contests only).

Year     One BF    Two BF    Avg. Time of Game    Avg. Time of 9-Inning Game
2019      1100      1054           3:10                      3:05
2018      1145      1143           3:04                      3:00
2017      1119      1091           3:08                      3:05
2016      1182      1075           3:04                      3:00
2009      1118      1066           2:55                      2:51
1999       980       904           2:57                      2:53
1979       439       411           2:35                      2:31
1959       161       211           2:34                      2:31

I see no correlation between more one- and two-batter relief appearances and longer games.

The average time of game increased by two minutes in both of these comparisons:

(A) 2019 to 2017 (56 fewer one- and two-batter appearances)

(B) 2009 to 1999 (300 more one- and two-batter appearances)

There were 105 fewer one- and two-batter appearances in 2018, as compared to 2016, but the average time of game remained the same.

From 1959 to 1979, the number of short relief appearances more than doubled (372 to 850), but the average time of a nine-inning game remained exactly the same.

Comparing 2019 to 2009, there were 30 fewer one- and two-batter appearances (which is statistically insignificant: an average of one such outing per 80 games), but the average time of game increased by 15 minutes.

If the average length of games in seasons ten years apart increased by 15 minutes, but the number of one- and two-batter relief appearances was almost unchanged, then there obviously is another reason for that dramatic time difference.

Someone should tell Commissioner Manfred.