30 June 2006
No Update Today; Changes Coming...
As stated previously, I'm using FanGraphs for tracking win probability added. For whatever reason, they have updated their daily tracking of yesterday's games, but not incorporated them into the seasonal stats, which is what I use. Since it's about 7pm here on the East Coast, and Friday to boot, I'm calling off today's update.
But when the next update comes, there will be more that's new than just the current stats. For the list of changes, hit the jump.
Tango gave some unexpected but much appreciated input yesterday, which I will be implementing in the next update.
These two make their appearance because clutchiness is now calculated as WPA Wins - LevOPS Wins. The whole gist of the comparison has been that stats like OBP and SLG are examinations of a player's production over all at-bats equally, while WPA uses leverage to judge value by production in certain, more important (higher leverage) at-bats. But while OPS Wins looks at every at-bat as equal, it also sees them in a vacuum. If the intent of clutchiness is to determine extra value added over what we expect, as Tango points out, it makes more sense to incorporate a player's seasonal leverage total with his OBP and SLG totals to better determine what we value we should have expected him to add. That is to say, if a player has, over the course of the season, come to bat in low leverage situations, we should lower our expectations for how many wins above average he could contribute. Obviously the converse applies as well.
All of these changes are being made in order to better evaluate a player's clutchiness, which is of course the intent of this exercise. It's a bit more work, but I'm glad to do it; anything in the name of clutchiness. ¶ 6:55 PM
But when the next update comes, there will be more that's new than just the current stats. For the list of changes, hit the jump.
Tango gave some unexpected but much appreciated input yesterday, which I will be implementing in the next update.
- OPS Wins Per PA are now calculated by the formula .025 * ( 1.7*OBP+SLG-1 ) for more precision.
- Two new columns appear on the stat page: Leverage Index (LI) and Leverage-adjusted OPS Wins (LevOPS Wins).
- Leverage Index is explained here and has been at the crux of clutchiness already. The reason a player's seasonal leverage is being included is to better elucidate LevOPS Wins
- LevOPS Wins is simply OPS Wins multiplied by LI.
These two make their appearance because clutchiness is now calculated as WPA Wins - LevOPS Wins. The whole gist of the comparison has been that stats like OBP and SLG are examinations of a player's production over all at-bats equally, while WPA uses leverage to judge value by production in certain, more important (higher leverage) at-bats. But while OPS Wins looks at every at-bat as equal, it also sees them in a vacuum. If the intent of clutchiness is to determine extra value added over what we expect, as Tango points out, it makes more sense to incorporate a player's seasonal leverage total with his OBP and SLG totals to better determine what we value we should have expected him to add. That is to say, if a player has, over the course of the season, come to bat in low leverage situations, we should lower our expectations for how many wins above average he could contribute. Obviously the converse applies as well.
All of these changes are being made in order to better evaluate a player's clutchiness, which is of course the intent of this exercise. It's a bit more work, but I'm glad to do it; anything in the name of clutchiness. ¶ 6:55 PM
