from Amazon
Monday, August 29, 2011
Poz and WPA: the story stat
Studes calls WPA the story stat. A win expectancy chart (and its associated leverage index) gives you a numeric representation of how you feel watching the game. Imagine that, how you feel, quantified.
Well, Poz unearths a gem of a game with WPA:
Well, Art Shamsky had the greatest WPA ever for a single game. His performance is the very peak of what man can do to win a baseball game. He homered to give his team the lead in the eighth, homered to tie it in the 10th, homered to tie it again in the 11th, there is not much more a baseball player can do. And so what happened? Art Shamsky’s Reds lost to the Pirates that day.
His WPA was +1.50. Remember, with every team starting at 0.50, this means the winning team, as a team, will be +0.50, and the losing team will be -0.50. With Shamsky at +1.50 as the losing team, this means that the rest of the team was -2.00!
Poz asks:
WPA—Win Probability Added—is one of the most interesting statistics out there, and to be honest I do not see why it has not become more popular among mainstream baseball fans. Maybe it needs a better presentation, a better name, a public relations person because WPA, it seems to me, speaks so clearly to what so many baseball fans love about baseball: The winning plays.
And he’s right. WPA was first presented back with the Mills brothers 40 years ago. The first time I talked about WPA was the day after the Cubs/Marlins game, easily the game where you can feel that something huge was happening after every play. And when I posted it on my blog, the readers immediately got it. (also see above chart)
Why do some people give it a bad rap? Because they take the stat out of its comfort zone, the story stat, and lump it in with other stats, where they then try to dissect it, expose its limitations, and then decide that because of those limitations, it has no value whatsoever! It’s like looking at OBP, seeing its limitations (BB = HR), and then deciding it’s crap. Imagine that. The person doesn’t know how to use a screwdriver, and then complains that it can’t hammer in a nail. “Why do we need a screwdriver if I have a nail?” Well, how about I have a screw, and I need that Philips?
I believe the best way to sell WPA, WE, and LI is to hammer home those Cubs/Marlins/Game6 types of games. Because those games can be explained, to a certain degree, numerically. And once you can do that, once you have a process that you can categorize emotional games on a numeric scale, it then becomes possible to find games like Art Shamsky’s.
That’s why we quantify things: to find even more emotional games.
You’re exactly right. I’m surprised the mainstream media hasn’t taken to WPA when discussing the MVP races since it truly tells you which player was most valuable in terms of winning for his team from an offensive perspective (which is great for the mainstream media since they rarely take defense into account).