QUOTE (johnmd20 @ Aug 22 2009, 03:34 PM) index.php?act=findpost&pid=2523069
So instead of looking at the actual numbers, we're going to estimate the ball park factor and just assume Jeter is hitting worse at home and the park is helping it look better? So, hey, why use the stats at all? Let's just assume Jeter is getting a lot of help from the ball park and despite the fact that he's actually hitting .340 on the road, that bump is due to the new toilet. Gotcha.
Something from a recent main board post about being 5% as clever as you think you are comes to mind as an appropriate response here.
Basically, there are two possible explanations for the home/road splits we've seen from Jeter so far:
1) Jeter has, for whatever reason (or, most likely, no reason other than random variance), hit worse at home than on the road, but has benefited from the park factor, meaning that the observed split is not pronounced.
2) Jeter has hit more or less identically well at home as on the road, and has not benefited from the park, so the observed split is not pronounced.
The second explanation is obviously simpler, doubtless explaining why casual fans would almost unanimously believe that it is correct. But why does it make sense to assume that the park - which results to date strongly suggest adds distance to fly ball trajectory, particularly to right field - has somehow failed to benefit Jeter's batted balls? That's far less likely to be true than the possibility of a random split in home/road performance, since you're dealing with a sample size of less than half a season in both cases.
When you have a sense of how a park adjustment works, it's prudent to apply it to all hitters unless there's a particularly good reason (handedness, GB/FB tendency, Hit F/X data) not to. Assuming that because a player's split does not point in the same direction as the park factor, that the park factor must not apply to that hitter, is entirely fallacious.
So instead of looking at the actual numbers, we're going to estimate the ball park factor and just assume Jeter is hitting worse at home and the park is helping it look better? So, hey, why use the stats at all? Let's just assume Jeter is getting a lot of help from the ball park and despite the fact that he's actually hitting .340 on the road, that bump is due to the new toilet. Gotcha.
Something from a recent main board post about being 5% as clever as you think you are comes to mind as an appropriate response here.
Basically, there are two possible explanations for the home/road splits we've seen from Jeter so far:
1) Jeter has, for whatever reason (or, most likely, no reason other than random variance), hit worse at home than on the road, but has benefited from the park factor, meaning that the observed split is not pronounced.
2) Jeter has hit more or less identically well at home as on the road, and has not benefited from the park, so the observed split is not pronounced.
The second explanation is obviously simpler, doubtless explaining why casual fans would almost unanimously believe that it is correct. But why does it make sense to assume that the park - which results to date strongly suggest adds distance to fly ball trajectory, particularly to right field - has somehow failed to benefit Jeter's batted balls? That's far less likely to be true than the possibility of a random split in home/road performance, since you're dealing with a sample size of less than half a season in both cases.
When you have a sense of how a park adjustment works, it's prudent to apply it to all hitters unless there's a particularly good reason (handedness, GB/FB tendency, Hit F/X data) not to. Assuming that because a player's split does not point in the same direction as the park factor, that the park factor must not apply to that hitter, is entirely fallacious.
