Re: MLB 2010: The Second Half
"But sorry, this is Joey Votto's year. He's in the top three in his league in just about every offensive statistic I care about. And he's first in six of the categories I care about most -- on-base percentage, OPS,
OPS-Plus, runs created, offensive winning percentage and Win Probability Added. "
help!!!
Win probability added is one I kind of like, though it has limitations (no inclusion of defense at all, for instance). At any given situation in a game (that is, what inning it is, what the score is, how many outs, runners on base), each team has a win probability, based on all the other games in the history of baseball that have had the same situation. So, to make up an example, let's say that Ryan Franklin is pitching to Joey Votto in the bottom of the 9th, two out, runner on first, Reds down by one run. In that situation, the Reds probably have a win probability that's only like 5% (0.05) and the Cardinals have a win probability that's like 95% (0.95). If Votto strikes out, his team loses the game, so their win probability goes from 0.05 to 0, and Franklin's team wins the game, so their win probability goes from 0.95 to 1. Votto gets -0.05 to his WPA, and Franklin gets +0.05.
Now, let's say Votto hits a homer and the Reds win. His team's win probability goes from 0.05 to 1, and the Cards' win probability goes from 0.95 to 0. Votto gets +0.95 to his WPA, and Franklin gets -0.95. You aggregate those additions and subtractions over the course of the season and you get an overall WPA for the player that measures (in one way, anyway) his contribution to the team's chances of winning. It's interesting because it includes clutch performance (a HR in the above situation is worth a lot more than a HR in the top of the 2nd, a HR in a close game is worth more than a HR in a blowout), but like I said it doesn't include defense at all, and... hmm, I know there are some other notable flaws with WPA, but my brain is kind of fried at the end of the week and I'm not coming up with them right now.