Loss Shares
November 12, 2003
I’m treading gingerly here. James spent a couple of pages describing how complicated the concept of Loss Shares is. On the one hand, he acknowledged their importance. On the other, he said that they are so complicated—particularly in their ramifications—that he couldn’t figure them out in the four years he spent working on them. Charlie Saeger, in a comment under the Bonds article, says that he feels they are unworkable.
Still, I can’t resist. I’ve come to realize that the Win Shares story isn’t complete without them.
Why are they so important? Well, let’s pick on the Mets and two of their good rookies: Ty Wigginton and Jason Phillips. These two guys both created eleven batting Win Shares last year, so they look like they contributed the same value to the team. But Wigginton made 449 outs creating those Win Shares, while Phillips made 306 outs. So Phillips created the same number of Win Shares using one-third less outs.
More background: Wiggy had 77 Runs Created vs. 65 for Phillips. Wiggy created 4.6 runs per 27 outs, vs. 5.7 for Phillips (league average was 4.5). Who added more value to the woebegone Mets?
The Win Shares system answers this question by setting the Marginal Runs threshold at 52%. If the threshold were set higher, it would favor Phillips. If it were set lower, it would favor Wigginton. Why? Because the 52% is applied to the average runs per out TIMES the number of outs by the batter. It dilutes Wigginton’s outs to the point at which he is equal to Phillips in team value.
Think of it this way: Wigginton is about equal to the league average in runs created per out. So if the threshold were set at 100%, his batting Win Shares would essentially equal zero. But Phillips would still accumulate batting Win Shares, because his runs created per out is above the league average. This is true regardless of the number of outs either batter creates.
Now, if the threshold were equal to zero (0!) percent of the average, then batting Win Shares would equal Runs Created, and Wigginton would have 77 to Phillips’ 65. The fact that Wigginton used more outs wouldn’t matter one iota. Wigginton would come out ahead in this scenario.
So it just so happens that 52% is the breakeven point for these two guys.
The irony here is that Win Shares clearly has a pseudo-replacement level, even though James claims that “there is no replacement level contemplated within this system.” You can’t have Marginal Runs without a threshold, and you can’t have a threshold without a “replacement” concept.
This is why the Win Shares story isn’t complete without Loss Shares. Loss Shares provide context for the Win Shares. Phillips created less losses because he created less outs, and this is important to know. Some folks like to refer to “Game Shares” to represent the number of games (outs divided by 27, essentially) that the player “played.” That’s okay too, because they would also provide context. Maybe Game Shares is the way to go.
I’m going to take a stab at this over the next couple of days. If anyone has any suggestions, let me know.
Thanks for your message, Tom. I’d suggest you leap ahead and read the “Win Shares Baseline” article and subsequent discussion. In particular, I’d suggest you note the reference to Bonds and Pujols in the comments section.
I think the answer to your question totally depends on who replaces Phillips when he’s on the bench. This is the replacement level concept, and it’s one that James admitted was lacking when he published Win Shares. I like to think that I’m carrying on, in some small way, the work he conceded was still required.
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studes on 01/07 at 10:53 PM
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