Monday, July 23, 2012

What the Win stat tells us

Sam Deduno pitched 6.1 innings
Sunday to get his first MLB win.
Sam Deduno on Sunday became the 17th Twins pitcher this season to be credited with a Win.

There are some prominent bloggers — the esteemed Aaron Gleeman among them — who ridicule the Win statistic. It is a rare day now when I don't encounter an online opinion saying, at least implicitly, that the W is useless and should be abandoned.

I see things a bit less black-and-white. All stats, to some degree, are flawed. Nothing stands perfectly alone. Hit a fly ball in Wrigley Field one day, it's a home run; on another day, with the wind blowing in, it's an out. Hit a grounder in the hole with Luis Aparicio at short, it's an out; hit the same grounder with Ron Washington at short, it's a base hit.

And all attempts to winnow out the various biases that infect the traditional stats depend so heavily on assumptions and formulas as to resist understanding or audit. There are at least two different formulas for WAR — Wins Above Replacement, a favorite of the current generation of sabermetricans — and those formulas can come up with drastically different results depending on how they "measure" defense and how they weigh home field biases.

The Won-Loss record has this advantage to it: If a pitcher is credited with the Win, his team won the game. If he's charged with the loss, his team lost the game. Winning and losing is the whole point of the competition. It's simple, it's easy to understand, and it's directly tied to the outcome.

The pitcher's win stat isn't as meaningful as it once was, and it was probably never as meaningful as the consensus once held it to be. The rise of bullpens, the coming of the five-man rotation, the monitoring of pitch counts -- all these changes have whittled away at the innings worked by starting pitchers, and the fewer innings worked by the starters, the less significant the Win becomes.

So the Win's meaning is fading. But discarding information, even if it's flawed, does nobody any good. Understanding the limitations of the information is the key.

So ... we look today at the Twins wins this season, and we see that Scott Diamond leads the team in Ws with eight. Next comes middle reliever Jeff Gray, 5-0 despite an ERA of 4.73. He's followed by Nick Blackburn, who has four wins and a bloated 7.46 ERA. Two have three wins (Francisco Liriano and Alex Burnett) and then 12 others have either two or one.

And I do see some significance to this. That the team's scarce wins are so spread out, that two of the top five in wins are middle relievers, are symptomatic of the failure of the starting rotation. There are other markers telling us that the rotation has been horrid, of course, but this is an obvious one.

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