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Subject: BallPark Adjustment Factors Posted by: Madman - [21222614] Tue, Apr 18, 12:42 I've been struggling with how to compute ball-park adjustment factors to supplement information I've posted up in some other threads regarding points scored against various teams, etc. For example, Total Baseball would report the ballpark factor for Kaufmann Stadium by taking the total of all runs scored in games at Kaufmann divided by the total of all runs scored in games in which the Royals played elsewhere. They then adjust this for an "other park" factor (they want to calculcate Kaufmann stadium relative to a generic league-average park rather than just the 13+ other stadiums that KC will play in for their road games). I am thinking about computing a similar index, but using points scored rather than runs. But I'm not sold on a) this notion of a ratio, and b) somewhat confused regarding the viability and/or importance of the other-park adjustment factor. I suppose the bottom line is to determine what it would be used for . . . Any helpful comments or ideas would be appreciated. | ||||||
| 1 | Species ID: 714729 Tue, Apr 18, 13:01 |
Madman - I could certainly see the validity to such an exercise, especially in terms of Echelon where there are unlimited trades. My *guess* is that, aside from Coors Field, that most SW Managers wouldn't see enough value in ballpark adjustment numbers due to the trade constraints to make good use of the data. As an active Echelon manager, I would LOVE to see this data. The one pitfall of course is the very limited sample at the new ballparks..... | |||||
| 2 | beastiemiked ID: 193161812 Tue, Apr 18, 13:25 | Don't forget about Enron field. I routine fly ball in this park is a homerun. | |||||
| 3 | Gary ID: 3538819 Tue, Apr 18, 13:39 |
How about just comparing ball parks not teams that play in that ball park.
Ex: take points scored in lets say Coors Field / by avg. points scored in all other parks. That should give you a # like .532 or something. You then could use this # as a factor in determining other data you might have stored. Understand what I am trying to say? Gary | |||||
| 4 | Species ID: 714729 Tue, Apr 18, 13:52 |
beastiemiked - The point of my last sentance was that the data for Enron is just too limited. Madman runs a pretty tight statistical model for the most part (I wasn't on the boards last year, Madman, but WaB says you do this stuff right!), and incorporating 1 homestand's worth of data in his exercise isn't likely to produce reliable data. Coors has years of data from which to base adjustment factor data from and is absolutely valid. Enron, at this point, is still a bit up in the air as to the exact benefit to hitters. | |||||
| 5 | Guru ID: 330592710 Tue, Apr 18, 14:10 | Gary - I think the problem with your simple approach is that (in your example) it is heavily influenced by the Rockies. The Rockies play in every game in Coor's Field, but they play in very few games in other parks. The approach suggested by Madman would largely neutralize that factor. | |||||
| 6 | Gary ID: 3538819 Tue, Apr 18, 14:18 |
I understand but it would also be true for the Braves, Astros, Cards, ext. wouldn't that cancle that factor out?
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| 7 | Guru ID: 330592710 Tue, Apr 18, 14:23 | No. | |||||
| 8 | Gary ID: 3538819 Tue, Apr 18, 14:24 |
LOL- Nice, Simple, concise.
I like it Gary | |||||
| 9 | dgreds ID: 35256248 Tue, Apr 18, 14:26 | Is there really any point to doing this during the season? There could be some flukes since you'll be dealing with such small sample sizes. This would be an interesting thing to post but not just looking at this season but at the last few seasons. I don't think that there would be any point in updating this b/c just because one week there are three shutouts at Coors doesn't make it any less of a hitter's park. It could just be a fluke. | |||||
| 10 | Madman ID: 21222614 Tue, Apr 18, 16:39 |
One would expect larger samples to provide more precise estmates. Therefore, it would indeed be better to have the data for the past years. Do you know of any place that would have a listing of all starts and stats that I could get my hands on? In lieu of that data however, we have to do the best that we can. Unfortunately, the way I have the data set up right now doesn't lend itself to reporting standard errors without a bit of work. If we truly had independent draws, I have every confidence that small sample sizes would not be a problem. We already have a few ballparks with 18 starts that have taken place in them. At the moment, there will be some significantly poor estimates, however, because each of the observations are clearly not independent. For example, St. Louis' road games are a reflection primarily of Coors field. This would seem to make StL look like a good pitcher's park. Of course, once St.L has gone to a wide variety of parks, we will have much better information, but until then, ouch. But the idea of a statistic that would aid in determining the most likely costs or benefits of various localities has tremendous use, even if slighly flawed (as long as the flaws are systematic, the numbers in special cases can be ignored by the knowledgeable observer). Plus, by doing it this year, we will have access to it next year . . . Gary -- The Guru's got it (as usual). For example, let's hypothetically assume that the Rangers have a great offensive team and somewhat questionable pitching. If you just look at the points scored at Arlington, you'll find that there aren't very many (pitching points, anyway). Does this mean that Arlington is a bad park to pitch in? Not necessarily. It could just mean that games that the Rangers play in are games in which a lot of runs are scored. That's why one should probably take the ratio of points scored in a park relative to points score in other parks (by the same teams involved). Although I'm having some difficulty with that given the preponderance of negative point outings in some parks. Sorry for the long post. | |||||
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