Friday, March 23, 2007

There's gonna be a play at the plate

For those of you who read my post concerning the determining factors of a sacrifice fly. I had a little bit of time to look over the effect of baserunner speed on the sacrifice fly scenario. Again, I'm working with a Retrosheet data base of all flyballs caught by an outfielder with less than two outs and a runner on third from 1993-1998. I calculated the speed score using the Bill James formula (I'm not a huge fan of the measure -- here's a better one -- but James will do for now) for each runner in the particular year in question. Again, I used a binary logistic regression. Did speed predict whether or not the batter broke for home? Not really. The regression coefficient was significant, but the Nagelkerke R-squared was about 1%.

Pardon me while I yawn.

Did speed help our erstwhile runner make it home? No, although this time the R-squared value made it up to a whopping 1.1%.

I re-ran the analyses with three predictors: distance, speed, and the interaction of the two (speed * distance). In that model, the distance from home plate was the only significant predictor of whether or not the runner ran and if he did, whether he made it. So, why doesn't speed make a difference?

Consider the following: the world record in the 100m dash is currently 9.77 seconds. Given that a meter is roughly three feet, a 30m dash would likely take around three seconds. (For the record: Yes, I know that the runner has to accelerate to full speed. Stay with me, folks.) I can run 100m, presuming that there's a water break around the 70 meter mark, in around 15 seconds. At that rate, it would take me 4.5 seconds to run 90 feet. So, the difference between me and the world's greatest sprinter is all of a second and a half over 90 feet.

I'll presume that even the fastest major leaguers are slower than Mr. Powell and that even the slowest are a bit faster than me. (Tonight, on the now-defunct Baseball Network, Victor Martinez and I will run a foot race!) So, let's say that the diference between the fastest and slowest runners over 90 feet is something in the neighborhood of one second.

If I didn't have to work on my dissertation, I'd take a look at the effects of speed on the situation of a runner trying to score from 1st base on a double. Over 270 feet, that difference in speed is now a matter of several seconds.

While I'm here:

Ryan Dempster is training to be a ninja? Is Roger Clemens syndrome rubbing off on Allan H. "Bud" Selig? Did the Braves just get the steal of the century by signing Brian McCann?

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