from Amazon
Thursday, August 13, 2009
The “Carry” of a Fly Ball
Blog-certified Physicist Alan Nathan:
Finally, all values of R/RN for that particular ball park are averaged together to obtain a quantity I refer to as the “normalized carry” for that park. By its very construction, the average of the normalized carry over all ball parks is necessarily one. A value of normalized carry greater than one means that the ball carries better than average; a value less than one means that the ball carries worse than average. The normalized carry for each ball park is shown in the plot below, arranged in ascending order of carry. The average value of 1.00 is indicated by the red horizontal line. Standard errors in the mean values are indicated by the flags.
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The striking thing about the plot is that Denver is head and shoulders above all the other ball parks, with a carry about 7.5% larger than average. Roughly speaking this corresponds to an extra 30 ft on a home run relative to the average.
Now, if you remember, I showed the “average distance to fence” in a recent thread where I show, using Greg’s data, that the distance to the Coors fence is 387 feet. With the “adjustment” Alan is presenting here, the “effective” distance of the fence, for HR, is 357 feet. The closest “real” fence is Fenway at 364 feet. As you can see, Coors went from being the farthest real fence distance to the closest effective fence distance. I love it when it all works out so cleanly!