In Search of Lost Variance | Disciples of Uecker

Disciples of Uecker

We'd like to go to the Playoffs, that would be cool.

Following the loss of Prince Fielder, many prognosticators expect the Brewers to take a large step back from their franchise-high 96 wins  last season. However, looking at the players added and subtracted, it is not entirely clear that this pessimism is warranted. According to Fangraphs WAR, Prince Fielder was worth 5.5 wins last year. The Crew has gone a long way towards making up this loss by upgrading the left side of their infield from Casey McGehee and Yuniesky Betancourt, who combined for 0.8 WAR, to Aramis Ramirez and Alex Gonzalez, who are projected* to combine for 4.5 WAR next season, an increase of 3.7 wins. Following this (admittedly over-simplified) arithmetic, Mat Gamel, Prince’s nominal replacement at first base, only needs to be worth 1.8 WAR, which is slightly below average, for the Brewers to have succesfully replaced Fielder’s production.

What’s more, if you’re skeptical of Gamel’s ability to produce even that much, consider one of the new faces on the team, Norichika Aoki. If Gamel flops but Aoki can be an average major league outfielder, the team could move Hart to first base and install Aoki in right to again replace Fielder’s production. In other words, the Brewers have two players in Gamel and Aoki who are essentially wild cards, but if just one of them can produce on the level of merely an average player, then the team will have essentially filled the Prince Fielder-sized hole in its lineup and, all else being equal, can expect the same results as last season.

There’s the rub, of course, because behind the phrase “all else being equal” lies all manner of statistical sin. A team can never expect things to remain the same from year to year. Some sports fans cringe at the attribution of large swaths of a team’s performance to “luck”, which is why I chose to use the phrase “variance” in the title of this post. Whatever the reason for it, it is unlikely that the Brewers will sustain a .625 winning percentage in one run games going forward, which was the major driving force between their winning 96 games rather than the 90 games predicted by their run differential. Whatever the reason for it, it is unlikely that Ryan Braun will repeat his MVP season. This variance in outcomes is a fact of life, and despite some of their bad breaks, on the whole the Brewers benefitted from some good breaks last year, and can’t necessarily expect those to repeat.

So where does this leave the club? Despite the crudeness of the estimation I employed in the first paragraph, I feel comfortable projecting them as having roughly the same true talent as they did before the start of last season, and I think this is a perfectly fine position to be in. I thought the Brewers could be World Series contenders before the start of last season, and right now, I think they can be World Series contenders for this season. The point I wish to stress, however, is that saying the team has the same true talent level on the roster that they did last year is not the same thing as saying they will win 96 games again. It is highly likely that they will fall short of that, and when they do, all manner of commentators will probably point to Prince Fielder’s absence as explaining the difference. Don’t listen to them. This year’s team doesn’t lack the talent of last year’s; they may, however, end up lacking the good variance.

*This projection is based on Fangraphs FAN projections, which are actually based on a survey of visitors to the site. I’m using this because this is the only system they use for defensive projections, and thus the only projected WAR they have. I feel comfortable using them because the offensive projections are largely in line with what the regression based mathematical projection systems use, and the defensive numbers sound plausible.

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Comments

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  1. BadgerNoonan says: March 3, 2012

    I think you make a lot of good points here and that one-run issue could regress, but while a greater-than-.500 record in such situations is often just good fortune, this is not always the case. For instance, if you possess Mariano Rivera your “natural” winning percentage in such games is probably higher. I use Mariano because many closers build their rep on just the kind of good luck you’re speaking of and then people are surprised when they eventually blow up. We have enough of a sample on Mariano to discount this possibility.

    I think K-Rod and Axford are more like Rivera than they’re like oh, let’s say Matt Capps, and so I think this is actually more sustainable than some might think. I could be wrong of course. There’s a ton of ways luck can bite you. K-Rod is older, some people seem to think Axford will start again experiencing some of the control problems that plagued him earlier in his career, etc., but in general, luck as an explanation for narrow games in inversely proportional to the quality of the back end of the bullpen.

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