Macha, Ellis, and Idols of the Cave

Recently, I received copies of two articles/speeches given by Paul DePodesta the new GM of the Los Angeles Dodgers who formerly worked for Billy Beane in Oakland and Jim Hart in Cleveland. DePodesta was profiled a bit in MoneyBall which raised the level of interest in the sabermetric techniques employed by Beane et. al. In these two articles, the passage I found most interesting was an anecdote about A's manager Ken Macha and second baseman Mark Ellis. In full the passage is:


"Our manager now, Ken Macha, loves our second baseman Mark Ellis. Mark Ellis is a good player, he plays hard, and he plays every day. But he didn't have a very good offensive year this year, yet Ken Macha kept putting him in the lineup every day. It even got to the point late in the year where he started hitting him leadoff. We finally went to Ken and said, 'We like Ellis too, but he probably doesn't need to be hitting leadoff, and getting all these at-bats.' And his comment to us was, 'Ellis is a clutch hitter.'

I thought, 'OK, clutch is one of those subjective terms I'm not wild about,' so I went back and I looked at the numbers, and at that time during the year Ellis was hitting about .163 with runners in scoring position and two outs, which I think is a clutch situation. But I didn't say anything, we kept it under wraps. When we were getting close to the playoffs, though, we began talking about the way the lineup should work against the Red Sox, and at one point Macha was talking about putting Ellis leadoff. Finally Billy Beane, our General Manager, just couldn't take it any more, and he said, 'Ellis is hitting .163 with runners in scoring position and two outs. He's not clutch.' And immediately, Macha said, 'But he hit that game-winning home run off of Jason Johnson.'

'OK, that's right, but if you want to play that game I'm going to come up with a lot more instances where he failed than instances you're going to come up in which he succeeded.'"


I love this story because it shows is two biases (idols of the cave as Bacon called them) in human thinking that cause us to make poor decisions - looking for only those examples that reinforce our preconceived opinion (affirmation bias as DePodesta puts it) and the related inability to deal with large sample sizes only through observation. Macha thought that Ellis was a clutch hitter because he let the one affirming example he could think of color his positive perception of Ellis (which was likely formed based on other traits like his hustle and "grit") and was unable to accurately gauge Ellis' performance over his hundreds of at bats even though he likely observed each one.

It should be noted, however, that sabermetric wisdom dictates that many of the splits commonly tracked including clutch situations like 2 outs and runners in scoring position suffer from small sample sizes and so many question whether there is any clutch hitting ability at all. As I blogged about previously, the authors of Curveball found that there is some evidence that clutch hitting ability exists but it is fairly weak. And so one could argue that Macha may have it correct after all but that the sample size hasn't yet shown it. Hitting Ellis, the former Royal prospect, leadoff is more problematic because of his .313 OBP in 2003. He had a respectable .359 OBP in 2002 but alas we won't see whether he will improve this season since he will be sidelined all year with an injury.

This further highlights the need in baseball as in other disciplines to quantify observations and perform analysis absent subjective perceptions.