Last week I wrote about five pinch hits that most directly affected the outcome of the National and American League wild card races. That story got me thinking about pinch hitters in general: how often they're used, in what types of situations, and how often they succeed.
I decided to investigate.
Using Baseball Reference's indispensable Play Index, I unearthed a host of facts about pinch hitters during the 2011 season. I found the facts interesting so I'm sharing them with you.
A bit of background first.
I was especially curious about the types of game situations in which managers used pinch hitters. Leverage Index measures how important a particular situation is in a game, factoring in the inning, score, outs and number of players on base. In essence, the Leverage Index is highest in the later innings, with the score tied or close, and men on base. Early in the game with the bases empty, the Leverage Index is low. The average Leverage Index is 1 and is considered neutral. Ten percent of all real game situations have a Leverage Index greater than 2, while sixty percent have a Leverage Index less than 1.
Next I wanted to know how often pinch hitters increase their team's chances of winning the game. For that I looked to Win Probability Added (WPA), which measures how a player affects his team's Win Expectancy on a play-by-play basis. Win Expectancy is the percent chance a team will win based on score, inning, outs, runners on base and the run environment. It is calculated using data from every baseball game for which play-by-play information is available.
O.K. Let's get started.
First, games pitting American League teams against American League teams. With the designated hitter in use, we'd expect to see pinch hitters used less frequently as compared to National League games. And that turns out to be true.
There were 2,016 American League vs. American League games in 2011 and only 840 pinch hitters used. The term "used" is meant in its broadest sense, to include those pinch hitters who were announced, but then called back for another pinch hitter before getting an official plate appearance. That happened four times.
A majority of these pinch hitters (664) had only one plate appearance in the game; 130 had two plate appearances. The rest had either three, four or five plate appearances.
For those 664 pinch hitters who had only one plate appearance, 34% entered the batter's box with a Leverage Index greater than 2.0; 44% faced a Leverage Index less than 1.0. In these games, then, pinch hitters were placed in high leverage situations to a significantly greater degree as compared to all game situations.
And how did these pinch hitters fare? Only 173 -- or 26% -- had a Win Probability Added greater than zero. The rest either did nothing to help their team's chances of winning or made matters worse.
The pinch hitter who faced the highest Leverage Index in a single plate appearance in 2011? Jake Fox of the Baltimore Orioles. On August 30, he came to the plate in the bottom of the ninth, runners on first and second, one out, with the Orioles trailing the Toronto Blue Jays 5-4. Fox singled, tying the game. The Orioles won on the next at-bat.
Next, we'll look at National League vs. National League games. There were 2,338 such games in 2011 and 3,938 pinch hitters used, or roughly 1.7 pinch hitters per game. Obviously, without the designated hitter, National League managers rely on pinch hitters considerably more than their American League counterparts. They also announce, and then pull back, pinch hitters more frequently than American League managers; they did it 51 times in 2011. Lefty, righty, lefty, righty,
Of the 3,938 total pinch hitters used, 3,523 saw only one plate appearance. Of these, 856 -- or 24.3% -- faced a Leverage Index greater than 2. Again, that's significantly higher than all real game situations, but significantly lower than in American League-only games. And that's no surprise, as National League managers use pinch hitters to replace pitchers, even in neutral Leverage Index situations, and American League managers do not.
And how did these pinch hitters perform? Only 991 of them -- or 28% -- had a Win Probability Added greater than zero.
Brett Hayes of the Florida Marlins faced the highest Leverage Index in a single pinch hitter plate appearance. On June 3, Hayes came to the plate with the bases loaded, two outs, and the Marlins trailing the Milwaukee Brewers by one run. Hayes struck out and the Marlins lost.
What about interleague games? Do National League managers act more like their American League colleagues during interleague games played with the designated hitter?
Let's take a look.
There were 129 interleague games played in American League ballparks. In these games, 54 American League pinch hitters were used and 69 National League pinch hitters were used. Conversely, there were 123 interleague games played in National League ballparks. In these games, 192 National League pinch hitters were used compared to 173 by American League teams. With or without the designated hitter, National League managers were more likely to use a pinch hitter in 2011 than the peers in American League uniforms. Not terribly surprising. Major-league managers are nothing if not creatures of habit.
Which manager used the most pinch hitters in 2011? In the American League, the winner by a wide margin was Joe Maddon of the Tampa Bay Rays. He sent 137 pinch hitters to the plate. Ned Yost of the Kansas City Royals used the fewest, only 36 pinch hitters all season. In the National League, the pinch hitter king was Terry Collins, manager of the New York Mets. He went to his bench 312 times in 2011. Don Mattingly, the skipper for the Los Angeles Dodgers, used the fewest -- 233.
And there you have it. A bit of pinch hitter trivia from the 2011 season. There's so much more buried in Baseball Reference's Play Index. When you have six or eight hours with nothing to do, check it out.