The guy who revolutionized baseball stats had a simple insight: past performance is a good indicator of future performance.
The stock market doesn't follow that rule, but an awful lot of human performance traits do.
The question one must ask before ignoring the past performance rule (if you're doing a job interview, say) is, "what am I replacing the Bill James rule with?" We need to understand how we're predicting the future if we're abandoning the idea of using the past as a guide.
If you believe that pleasant interviewing skills, a good handshake or the right outfit are a better predictor of future performance than what the person has actually shipped in the past, I think it's worth pointing out that you're nuts.
And if you're the one who's hoping to be interviewed one day, it seems as though the best way to market yourself isn't with a slick resume or the right suit. No, the most reliable form of self marketing is to have a long history of stunningly great work, shipped.
[Karen writes in to point out that many people break this rule, accomplishing something great right out of the box. And well they do. In fact, if you do it a few times, then, in Karen's words, "I'll just keep breaking the Bill James Rule, until I become proof of it."]