Oh the stories numbers tell: Clemens, lies, and statistics
There’s a piece in the New York Times called Report Backing Clemens Chooses Its Facts Carefully that takes an exhaustive look at Roger Clemmens’s statistics in an effort to make the case that there’s nothing special about his success in his later years. Here’s a clip from the article . . .
The report hinges on a critical question: Was Clemens’s late-career success highly unusual? If so, an unusual late-career improvement lends credence to the Mitchell report’s assertion that he used performance-enhancing drugs at various times from 1998 onward. The Clemens report tries to dispel this issue by comparing him with Nolan Ryan, who retired in 1993 at 46. In this comparison, Clemens does not look atypical — both enjoyed great success well into their 40s. Similar conclusions can be drawn when comparing Clemens with two contemporaries, Randy Johnson and Curt Schilling.
Yet such comparisons tell an incomplete story. By comparing Clemens only to those who were successful in the second act of their careers, rather than to all pitchers who had a similarly successful first act, the report artificially minimizes the chances that Clemens’s numbers will seem unusual. Statisticians call this problem selection bias.
Leaving aside the morality play unfolding around Clemens in particular, and performance-enhancing drug use by public figures in general, I offer this as another example of “lies, damn lies, and statistics.” In business we seem especially fond of numbers, parading them around is service of “fact-based decision making” and other lofty sounding terms. To which I would remind all of us that decisions find their roots in the stories we tell ourselves. Numbers just help.
So when you see someone loaded up with a bunch of numbers . . .
- Get your suspicious hat on.
- Buckle up.
- And pay attention to the story. That’s where the action is.
There are loads of questions you can ask, but that’s another subject..
You can read the full report at: http://www.rogerclemensreport.com/.
kah
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Tags: RogerClemens, Mitchell Report, decision making, statistics