THE BOOK--Playing The Percentages In Baseball

Tuesday, August 21, 2007

Streaks

Dave at USSM recaps the Streaks chapter from The Book and applies it to the Mariners.  This is the kind of stuff I’d like to see, applications of findings in The Book to real-life scenarios.  I think if you were to poll the fans, and give them the cases of Ibanez and Vidro (each over 30, each a career 110 OPS+, each with a 2007 OPS+ of around 110):
- Ibanez: OPS of 1.571 from Aug 7 - 20, with 9 HR in 13 games
- Vidro: OPS of .941 from Jul 12 - Aug 20, .395 BA in 33 games
- Adam Jones: rookie, career OPS+ of 49 with 100 PA, 37th pick in 2003, #10 MLB prospect by Baseball America

They might think: Ibanez has achieved a new level of performance, Vidro has turned the corner and become what he was in Montreal, and Adam Jones still needs to learn the craft. 

As Dave said, “because of our own biases, we’d make more correct decisions if we had less data”, or as MGL said, “One of the running themes of this book is that, very frequently, fans and analysts make too much from too little”.

The only thing I’d be confidant to say is that Ibanez and Vidro are probably not injured.  Unless these guys made a fundamental change in their skills (and this has got to be rare, otherwise half of the 750 players will qualify), I doubt we’ve seen any real change here.  My guess is that the OPS of these two players will be around their career norms, from Aug 21 to the end of the season. 

Of course, I can’t pin my hopes on just two guys.  It would be more interesting to run a poll on blogs for all 30 teams, and see which players fans think has “turned it around”.  I’d bet most of them would revert to their careers norms the rest of the way.