It’s been a while since I looked at Win Probability Added, since I’m not really keeping my own stats like I have in past years (I use Excel web queries of FanGraphs to get my data). No one would likely be surprised by the Braves’ leaderboard, which is topped by Jair Jurrjens and Chipper Jones.
WPA, as perhaps the king of all-encompassing stats, has some flaws. Defensively, it doesn’t consider the impact of fielding (at least it doesn’t on FanGraphs). The impact of closers and other elite relievers is magnified because of their typical usage patterns (late in close games). It’s also not very predictive because it includes the impact of clutch performance, which is highly variable.
If you’ve read this blog for any length of time, you’re aware of all that, and you also know that you can make an adjustment to WPA that removes the important clutch component. Dividing WPA by Leverage Index (LI), a measure of a situation’s importance, leaves us with something that’s much more predictive: WPA/LI. In simpler terms, WPA/LI tells us less about what happened and more about what’s likely to happen in the future.
Below, I’ve presented each Brave’s WPA/LI for the season. A WPA/LI of zero theoretically means that a team full of that player would play .500 baseball. A team with 25 players who have +1.0-win talent (over a full season) would finish 106-56, 50 games over .500 (+25 wins vs. 81 wins). I’ve also presented the same as a rate per 100 “events,” which would include plate appearances for hitters and batters faced for pitchers. I’ve called that W/100. Pitchers’ hitting is included in their totals, and stats are through Sunday.
(Note: If your monitor has a screen resolution lower than 1024×768, you may have trouble viewing the image. Try “zooming out” with your browser if you can’t see the whole thing. I didn’t want to reduce the size any more, since the bars and labels were already pretty small.)
The red bars are WPA/LI, and the blue dots are W/100. The only meaning to derive from the placement of the dots vs. the red bars is that some players have had more opportunities than others. Eric O’Flaherty stands out as an example of quality performance in limited opportunity. Lowe/Vazquez/Jurrjens stand out on the other end of the spectrum with positive performance over a lot of opportunities.
If the Braves could get Garret Anderson’s and Jeff Francoeur’s bars to look neutral, more like Matt Diaz, they’d be in business. It’s hard to believe that Anderson has been as bad as Buddy Carlyle on a per-PA basis, especially when that doesn’t consider his poor defense.