There were some recent posts around the blogosphere on clutch hitting. As many times before, the discussion was mainly about whether or not it exists. Here are the links:
Overestimating the Fog by JC Bradbury at Sabernomics. This article got discussed at Baseball Think Factory. JC Bradbury also posted two other studies: Does Clutch Pitching Exist? and A Little Clutch Hitting Study. Phil Birnbaum had Doesn't "The Book" study pretty much settle the clutch hitting question?.
Bradbury's "Fog" article refers to an article from a few years ago by Bill James (JC has a link to it). Bill James suggested that our statistical methods might not be able to detect clutch hitting. JC has presents a different view.
Phil makes a refernce to "The Book" by Tom Tango, Mitchel Lichtman and Andrew Dolphin. Their basic finding was that there is clutch ability but it is very slight.
Now getting back to Bill James. He wrote an article a couple of years ago called Mr. Clutch: Big Papi, Chipper, Pujols come through when it counts. James said:
""Clutch" is a complicated concept, containing at least seven elements:
1. The score,
2. The runners on base,
3. The outs,
4. The inning,
5. The opposition,
6. The standings,
7. The calendar."
Then he showed how certain players did alot better in these cases than they normally do. But what he does not say in this article (it may be elsewhere), is how much differently all players hit in these situations than they normally do (that is, the league average differential). This information is necessary to see which players' clutch performance is statistically significant. I made a crude attempt at analyzing James' new measure of clutch in this post: Is David Ortiz A Clutch Hitter?. For differences from normal performance, I used those in close and late situations. It looked like his clutch performance was not significant. But I have not seen James post the clutch data for all players, so a complete analysis has not been done (maybe he has posted this on his site but I have not signed up to pay for it).
I did a study a few years ago called How Many Games Do Clutch Hitters Really Win?. I had two methods of seeing how many wins clutch hitters added above their normal hitting. In one method, only about 10% of the hitters I looked at were able generate as many .5 more wins a season than expected by hitting better in the clutch than they normally do. That assumes that this was thier true clutch ability. In the other method, only 3 out of 71 players added as many .5 wins (that table is partly cutoff now at the link).
Getting back to what "The Book" says, they show that the biggest clutch hitting skill of any player over the 2000-2004 period was .0018 on their wOBA stat (based on another formula they mention, I estimate that is about .004 in OPS). Their clutch situation was the 8th inning or later and the batting team is down 1-3 runs. I don't know what percentage of all plate appearances are made up by these situations, but for close and late situations (CL) it is 15%. My study, mentioned in the previous paragraph, found only a small number of hitters making much difference by their clutch performance and I made no "regression to the mean" adjustment to their clutch stats like "The Book" people did.
I assumed that if a guy's OPS was .050 higher in the clutch than otherwise, that was his true clutch ability. If "The Book's" clutch situation is also about 15% of the PAs (like CL), then I have to assume that their methods say that players add many fewer wins from their clutch performance than my method since my method has a top differential of .117 for Tino Martinez. That is, his OPS was that much higher in the clutch than otherwise. They have a biggest difference of about .004 in OPS, which probably creates very few extra wins. And that is the best they found.
Phil Birnbaum's post also mentioned how different kinds of hitters, like power hitters vs. singles hitters, hit differently in the clutch and whether or not it was due to a change in their approach with the game on the line. I did a study once called Do Power Hitters Choke in the Clutch?. It was inspired by a study by Andrew Dolphin (one of "The Book" people-I have a link to it at this study). I found mixed results, but maybe powers did do a little worse in the clutch than other hitters.
Finally, if clutch hitters are real, do teams make trades to get them? Do they offer those free agents more money? I would love to know if teams have ever done this. There is a study on this called Are Players Paid for "Clutch" Performance? by Jahn K. Hakes and Raymond D. Sauer. My guess is that teams never consider any clutch data when making personnel decisons. If that is the case, then effectively clutch is a non-issue.