At some point during last season Studes, of
Baseball Graphs and
The Hardball Times, introduced
Win Probability Added in graphical form. I emailed him at the time asking how I could calculate it for Sox games. He explained that it was complicated, and cited some stuff that went way over my head.
The short explanation of Win Probability is fairly intuitive. You probably calculate your own form of it in your head. You know that runs are good and outs are bad, and in close games runs and outs become more valuable at the end of the game because there's less time left in the game.
A longer explanation, from Studes, might make this clearer.
Here's the basic idea. An average team, at any point in a game, has a certain likelihood of winning the game. For instance, if you're leading by two runs in the ninth inning, your chances of winning the game are much greater than if you're leading by three runs in the first inning. With each change in the score, inning, number of outs, base situation or even pitch, there is a change in the average team's probability of winning the game.
And that's what leads to this chart. This chart tracks the probability of a Sox victory in yesterday's game.
In addition to being able to track the probabilty of a Sox victory, WPA allows you to track each player individually. Each indiviual out, hit, stolen base, error, etc. adds or subtracts from your likelihood of winning. By tracking each individual play, we can come up with an expression of what each player contributed to the game, positive or negative.
It's possible for a player who goes 1-4 to have a greater WPA than one who goes 2-3 with a HR. This is, as Hawk would say, "don't tell me what you hit. Tell me when you hit it." Who knows, maybe Timo contributed more than I thought last season.
Here is each players win expectancy added, divided into Offense, Pitching, Fielding, and Total.
Team Player Off Pitch Field WPA
Indians Hafner 0.151 0.000 0.000 0.151
Riske 0.000 0.095 0.000 0.095
Millwood 0.000 0.086 0.000 0.086
Crisp 0.025 0.000 0.000 0.025
Ludwick -0.024 0.000 0.000 -0.024
Belliard -0.028 0.000 0.000 -0.028
Blake -0.036 0.000 0.000 -0.036
Cora -0.068 0.000 0.000 -0.068
None -0.073 0.000 -0.006 -0.078
Broussard -0.083 0.000 0.000 -0.083
Hernandez -0.090 0.000 0.000 -0.090
Sizemore -0.124 0.000 0.000 -0.124
Martinez -0.176 0.000 0.031 -0.145
Boone -0.141 0.000 -0.016 -0.156
Indians Total -0.669 0.181 0.010 -0.471
Sox Garcia 0.000 0.399 0.000 0.399
Podsednik 0.164 0.000 0.088 0.251
Marte 0.000 0.108 0.000 0.108
Takatsu 0.000 0.098 0.000 0.098
Everett 0.078 0.000 0.000 0.078
Crede 0.063 0.000 0.000 0.063
Widger 0.029 0.000 0.000 0.029
Ozuna -0.053 0.000 -0.024 -0.078
Rowand -0.091 0.000 0.000 -0.091
Dye -0.097 0.000 0.000 -0.097
Konerko -0.099 0.000 0.000 -0.099
Iguchi -0.163 0.000 0.000 -0.163
Sox Total -0.169 0.605 0.063 0.500
Garcia, obviously, was the games most valuable player, with Podsednik being the most valuable hitter. Like I said, you probably already knew that intuitively. WPA just gives us the data to back it up. It would be interesting to see each players WPA totals at the end of the season. :ph34r:
