Comments on: Correlation, Causation, and Beat Writers

By: vj

vj — Wed, 20 Jun 2007 13:42:02 +0000

re Dave’s comment 111: seems like you’re starting to succeed, see Baker’s latest blog entry.

By: Chris Miller

Chris Miller — Wed, 20 Jun 2007 05:35:18 +0000

RA is better than ERA, especially at the team level, but also at the individual level.

By: heyoka

heyoka — Wed, 20 Jun 2007 05:30:42 +0000

I would propose that bad pitching causes high ERA, therefore making it a reliable stat for judging a team’s season pitching.*not individuals – sample size*
ERA+ would be better because it adjusts for park effects, but Baker is writing this article for the common fan, justifying the use of a rough stat.
4.50 seems arbitrary, but it’s a run every other inning, making it easy and understandable to use as a marker.

By: Ralph Malph

Ralph Malph — Wed, 20 Jun 2007 03:32:18 +0000

no one is attempting to run them on older seasons to see if the quantitative data is reflecting the qualitative perception.

No one?

By: Dave

Dave — Wed, 20 Jun 2007 03:01:15 +0000

Which stats are you referring to, dw? Win Probability is a mathmatical formula. It’s just win expectancy put into practice based on current run scoring environments.

By: dw

dw — Wed, 20 Jun 2007 02:55:09 +0000

My one issue with some of these newer stats is that no one is attempting to run them on older seasons to see if the quantitative data is reflecting the qualitative perception.

I’m reminded of how Bill James gave Craig Biggio insane value in the Historical Abstract, but then you look at Fielding Win Shares and see how he overvalued middle infield defense and wonder if Biggio was benefiting too much from that bump.

By: Evan

Evan — Wed, 20 Jun 2007 02:44:39 +0000

Okay, I get what you’re saying. Since you’re looking for value, you’re measuring anything that helped the team, regardless of whether is was the result of skill or luck.

I can see why people would want to count that in their MVP debate. I just think those people are wrong. It’s like giving credit to drunk drivers who don’t happen to hurt anyone.

By: Chris Miller

Chris Miller — Wed, 20 Jun 2007 02:17:58 +0000

For hitters Win Shares are nifty, as long as you ignore Fielding Win Shares, that’s where the value of winshares figuratively comes off it’s wheels while driving down the road.

By: Chris Miller

Chris Miller — Wed, 20 Jun 2007 02:16:07 +0000

I think someday in the future WPA will be useful for HoF voting, for example if someone outperforms their expected WPA consistently, that might serve as a shot in the arm for borderline cases. I think in ~ 15 years we should have a much better idea of which (current not past) players deserve HoF since we can look at their career via things like WPA and measure their career defense with things like UZR.

By: Dave

Dave — Wed, 20 Jun 2007 02:11:48 +0000

In the context of an MVP discussion, though, it carries some weight. Vlad hit a walkoff home run the other day off Chris Ray that was worth .65 wins. With a single swing of the bat, he turned a likely loss into a win.

That happened, and it had a tangible effect on the Angels record. It held a lot of value to the team.

He might not be able to keep hitting walkoff home runs every time he bats in the bottom of the 9th, but it doesn’t diminish the real contribution that he made with that swing. And, in terms of an MVP discussion, I can see the perspective that you should reward players for events that actually occurred.

I’m not sure I would vote that way, but I think there’s merit in the reasoning of those who would.

It’s when people try to use WPA or Win Shares or similar things to evaluate talent that it becomes a problem.