Sunday, 5 July 2009

Adventures in Independence Day Leverage

Yesterday's game is what baseball is all about, for me. The score wasn't too high, the game was dominated by pitching, and neither of the two contending teams gave up on the game.

During the game, I performed an exercise of calculating Leverage x Win Value in order to create a number that would represent the value of each event to winning the game. Instead of using the run value of each event, I used the win value as detailed in Tango, Litchtman, Dolphin's The Book. (Run values are used in the famous linear weights formula devised by Thorn and Palmer in The Hidden Game of Baseball.)

It was an interesting exercise, because it highlighted how a well-timed single can be far more valuable than a home run, and why on-base percentage is more valuable than slugging.

Dunn's home run in the bottom of the 7th, leading off, was worth 14.76 per cent of a win. But Zimmerman's single in the bottom of the 8th was worth 24.78 per cent of a win. Even Dunn's single in the next plate appearance was worth more than Dunn's homer, at 15.96 per cent of a win. By the time we get to Willingham's single, the cumulative effects of the runs scored up to that point have substantially reduced the leverage, and he only gets 4.62 per cent of a win.

The reason is the multiplier effect of leverage. The base runners and the differential in score added up to making those 8th-inning situations of greater significance. A typical linear-weights formula wouldn't have captured this, and just awarded Dunn a 1.44 runs for his home run and 0.44 runs for each of the three singles. Furthermore, it also accounts better for the effect of piling up baserunners, each additional runner pushes those already on base closer to home plate. Bard would not have scored from first on any of the Zimmerman-Dunn-Willingham hits; he had to get to second.

On another matter, anyone following this game would think bunting was a brilliant strategy. A bunt made the Braves' first run possible, and a bunt arguably resulted in the Nationals' being in a position to tie the game quickly, although in the subsequent walk meant the bunt really had no effect. I'm not trying to argue the point, just observing that in this game bunting worked.

Finally, I'm awarding a Hero of the Day to MacDougal, for defending the lead in the top of the 9th.

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