Quote:
Originally Posted by Garlon
I updated the original post with information on pitcher groundball percentage rating.
Pitcher Groundball Percentage:
From what I can tell, OOTP does not currently import pitcher groundball percentage accurately. This data exists for pitchers since 1916 on baseball reference but I do not know if the database has been updated. For 1871-1915 we have estimated team GB% that can be assigned to all pitchers on a given team for those seasons so that team GB% is accurate in the game.
In 2004 Kenny Rogers had a 1.07 GO:AO ratio, this is 1.07 groundouts per 1.00 airouts. Translating this to a groundball percentage is 1.07/(1.07 + 1.00) = 1.07/2.07 = .516 which rounds to 52%. He pitched 635 outs and struck out 126 batters, so 635 – 126 = 509 outs on balls in play. 509*.52 = 265 groundball outs and 509 – 265 = 244 airouts. It is important to calculate the groundball and airout totals when basing statistics on 3yrs and 5yrs, so that the seasons can be tallied and a proper weighted average found.
I started a 2004 replay and Kenny Rogers imports at 56%. The 2004 GO:AO ratio for mlb was 1.09, which is 1.09/2.09 = .521, which rounds to 52%. Kenny Rogers and the league are both 52%. In the editor we get 56% for Rogers and the editor says (54% = average) as a standard for OOTP. Even if OOTP was translating everything to a 54% standard, then Rogers being league average should receive 54%, but he is not. I do not know why pitcher GB% is not being correctly imported, but it needs to be corrected. We have pitcher data since 1916 and we can use estimated team data that I have in the teams file for pitchers from 1871-1915 so that we can get better imports for any season.
|
There's nothing wrong here. OOTP uses a slightly different calculation for GB/FB than for instance Fangraphs does or than raw GO:AO numbers. So the GB% in OOTP will typically be something like 4-5% higher than you'd see in most other sources. It's a difference in how we classify certain linedrives iirc, though I do not remember the specific details. Markus would know for sure.
Anyway, that's just how the engine is designed, and the difference is expected. In fact if we were to change the GB% for individual players like you're suggesting, without also redesigning the engine, this would actually lead to more inaccurate results.