Why Using 2009 Results to Predict 2010 Does Not Work, or Yes, Yuniesky Betancourt Can Only Get Better

Dave Cameron at Fangraphs has a nice article on the perils of using the prior year's result as the baseline for projecting the next year's results, including a few encouraging words on postive regression involving beloved Royal Yuniesky Betancourt

Regression “fixes” a lot of problem spots from the prior year, even if the team doesn’t make a serious effort to change out players. The Royals got a .253 wOBA out of their shortstops a year ago. I don’t care how bad you think Yuniesky Betancourt is, you have to expect that number to be higher this year. They didn’t do anything to improve their shortstop position this winter, but the level of production they got from the position in 2009 is not their expected level of production for 2010.

. . . .

This applies across the board. Injuries, clutch hitting, variance in run distribution – all of these are subject to extreme amounts of regression, and they all had a significant impact on how some teams performed last year, both in terms of “raw” wins and losses and things like runs scored and runs allowed. You cannot just look at a team’s prior year won loss record – or even their pythagorean record – make some adjustments for the off-season transactions, and presume that’s a good enough estimator of true talent for the 2010 team.

This article arrives a year too late to temper expectations for the 2009 Royals based on the 2008 Royals, but the underlying premise still applies, as the 2010 Royals may perform better than the 2009 Royals even if they really are not much better overall.   

Other Fangraphs goodness:

Our own devil_fingers envies the Orioles outfield and a quick yet effective analysis of comparing ERA with an advanced pitching metric (xFIP) further suggests that Luke Hochevar was one unlucky SOB in 2009 and is a good candidate to show improved results in 2010.   

This FanPost was written by a member of the Royals Review community. It does not necessarily reflect the views of the editors and writers of this site.

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