My first take on the clutch issue went nearly unnoticed more than a year ago.
Here I'm getting at it once more, having the benefit of both the wide audience provided by The Hardball Times and the data from FanGraphs.
Leaving aside questions such as whether clutch hitting does exist, let's try to define the traits of a clutch hitter.
First warning. My choice is to treat every game the same; i.e., a plate appearance with the game on the line is always important, no matter if it's a wild card race contest or a meaningless game between two teams out of contention. Other analysts will be able to replicate this study weighting for the importance of the game. (Yes, I'm looking at you and your Championship Leverage Index, Mr Sky Andrecheck.
Update: It appears that Sky is now an analyst for the Cleveland Indians; congratulations to him.
I think of a clutch hitter as someone who, whatever his underlying talent, does his best when the game is close and leaves his worst at-bats in mop-up situations. Thus, a player who has 10 home runs in his bat would be perfectly clutch if he hit them in the 10 most important plate appearances of his season; and at the same time he piled up his strikeouts in the most lopsided games.
Second warning. According to how I'm defining the clutch hitter, you don't necessarily want the clutchiest hitter at the plate in the deciding at-bat of the game. A perfectly mediocre hitter could be superclutch, but his production when the stakes are high might nonetheless be lower than that of a great batter with no clutch ability.
Two independent measures
The Run Value of an at-bat gives us a measure of how successful the batter was, without taking into account the base/out situation, the score, the inning. A home run is always considered worth around 1.4 runs and a strikeout close to -.3.
The Leverage Index, courtesy of Tom Tango, on the other hand, summarizes in a single number everything pertaining to the situation, while completely ignoring the outcome of the at-bat. And, most importantly, that number varies according to the potential impact the at-bat has on the final result of the game.
For the perfectly clutch hitter, sorting his plate appearances by Run Value would be equal to sorting his PAs by Leverage Index.
In more technical words, the correlation between the ranking of at-bats by Run Value and the ranking of at-bats by Leverage Index would be one.
In the real world we are going to find a lot of zero-correlations.
Here are the top 10 clutch careers (data starting from 1974, minimun 2,500 PAs), where the value under the column "clutch" is the correlation between the ranking of at-bats by Run Value and the ranking of at-bats by Leverage Index.
rank First Last clutch 1 Rodney Scott 0.068 2 Bill Hall 0.057 3 Willie McCovey 0.054 4 Garth Iorg 0.054 5 Danny Bautista 0.052 6 Jeff Reboulet 0.051 7 Thurman Munson 0.050 8 Brian Schneider 0.050 9 Jim Leyritz 0.048 10 Mike Matheny 0.047
And now the chokers (justifying the title of the article).
First Last clutch Nelson Liriano -0.033 Mike Lieberthal -0.030 Robinson Cano -0.030 Willy Taveras -0.029 Shane Victorino -0.028 David Dellucci -0.027 Eric Byrnes -0.025 Denny Hocking -0.024 Warren Cromartie -0.024 Tom Foley -0.024
As you can see even the most extreme performances show very weak correlations (those at the top come out as statistically significant, thanks to the huge sample size, plus the fact that looking for five percent statistical significance many times leads to finding it about once every 20 runs, by definition—but this doesn't make them strong correlations).
Plotting all the career clutch numbers as a histogram gives us a typical bell-shaped figure, only slightly skewed to the clutch side.
David Ortiz's famous 2005 season is not the clutchiest of the last quarter of century. Though pretty impressive (correlation .153) it's the 46th on my list, topped by Milton Bradley's 2000 season (minimum 150 PAs).
First Last Season clutch Milton Bradley 2000 0.232 Mike Matheny 2006 0.227 Jeff Reboulet 2000 0.224 Randy Ready 1990 0.204 Ivan Calderon 1985 0.203 Rick Miller 1977 0.200 Dan Meyer 1983 0.195 Luis Salazar 1985 0.192 Ben Oglivie 1981 0.191 Rafael Ramirez 1980 0.189
Speaking of Big Papi's career, here are his seasons with at least 150 PAs.
Season clutch 1998 -0.048 2000 0.071 2001 0.006 2002 -0.005 2003 -0.006 2004 0.007 2005 0.153 2006 0.033 2007 0.008 2008 0.015 2009 0.022
In his career, he posted just three seasons with negative correlations, compared to eight with positive correlations.
Other players have constantly beaten zero*, as you can see below.
* From now on, I'm loosely referring to seasons with correlation above zero as clutch and to seasons with correlation below zero as choke. Keep in mind that most of them are actually not significantly different from zero.
First Last clutch seas. choke seas. Dave Parker 16 2 Eddie Murray 15 6 Omar Vizquel 15 6 Carlton Fisk 14 5 Ozzie Smith 14 5 Paul Molitor 14 6 Gary Sheffield 14 7 Darrell Porter 13 1 Manny Trillo 13 1 Mark McLemore 13 2
Anyway, confirming findings by other authors, in general there doesn't seem to be anything persistent in clutch hitting: Plotting each player's clutch values in odd years versus the same player in even years we see absolutely no correlation.
Fangraphs clutch stat
Fangraphs has its own clutch number, calculated differently; but if you read the introduction to the stat, you'll see the definition of clutch hitting is absolutely in line with the one I've outlined a few paragraphs above. Here is a scatter plot of the two different measures of clutch hitting; the correlation is 0.569 (Confidence intervals: 0.555, 0.583)
In his celebrated book Weaver on Strategy, the Earl of Baltimore talks about Eddie Murray as a player who constantly delivered in important situations, while taking something off when the game was in the books. Seeing his name high in the previous table supports (however lightly) Weaver's impression. Murray never posted a season like Big Papi's 2005, but often had correlations on the positive side (see below).
Season clutch 1977 0.019 1978 0.022 1979 0.004 1980 0.057 1981 -0.077 1982 0.025 1983 0.028 1984 0.029 1985 0.071 1986 -0.044 1987 0.008 1988 -0.067 1989 -0.009 1990 0.092 1991 0.017 1992 0.028 1993 -0.046 1994 0.081 1995 -0.081 1996 0.008 1997 0.005
Perceived leverage, platoon, bullpen usage
Again, leaving aside the debate of whether clutch hitting exists, why don't we find greater clutch numbers?
- Players care about the outcome of the game, but also about their paycheck: When the batting average is used in contract negotiations, a hit in a meaningless at bat has the same weight as a hit in a crucial situation. Thus, it might not be always a good idea to relax when the result is set in stone.
- Say you are such a clutch hitter that you can play 20 percent better whenever you think it's showdown time; your perceived importance of the moment won't necessarily match with Tango's Leverage Index values.
- If managers used their bullpen efficiently, hitters would often face tougher opponents in high leverage at-bats; they would also likely have the platoon disadvantage.
For the reasons outlined above (especially the last one), I would have expected the histogram in the "Careers" paragraph to be slightly skewed toward the choke side, but the opposite is true.
Maybe the cause of this is the selection of players with at least 2,500 PAs, but I did a similar histogram (not shown here) for players with shorter careers and it had a similar right skewed shape. Any idea on that?
Finally a couple of links with the full lists of clutch values: careers - seasons.