Wednesday, 18 November 2009


Moving away from the Nationals postmortems for a bit, it's Hall of Merit time in the Sabermetric City. I was a latecomer to the Hall of Merit, but it's given me hours of fun. Just like last night!

To fill you in - I'd filed a preliminary ballot based on some people who'd been getting lots of votes, when I noticed from Rick Reuschel's Davenport Translationspage at Baseball Prospectus that he had an awful lot of WARP3. Anyway, I prefer to home-brew my own stats than use other people's. (Unless they are from the Big Bad Baseball Annual!) So, how to get a quick-and-dirty One Big Number for a pitcher?

I failed on the 'quick' part, but I made a stab at creating a Defense Independent Earned Run Average, based on Clay Davenport's article on his Fielding Translations in the 2002 Baseball Prospectus. Here's how it works.

Stats you need:
A pitcher's seasonal Games, Innings Pitched, Hits, Home Runs, Bases on Balls, Hit Batsmen, Strike Outs and Earned Runs.

1) Create a new category, called FldgHits. Subtract Home Runs from Hits.
2) Multiply the IP by 3. Subtract strikeouts. Take 30% of that number and add the strike outs back in. Divide by 3. This is 'PitchIP'.
3) Use a modified version of Equivalent Average and calculate the PitchingEqA and the FieldingEqA as follows
Pitching (2*(30% of FldgHits))+(3*HR)+(1.5*(BB+BP))/(IP*3)+(FldgHits)+BB+HBP
Fielding (2*(70% of FldgHits))/(FldgHits)+(IP*3)
4) Divide the PitchingEqA by the FieldingEqA.
5) Subtract 1 from the ratio in step (4). This gives you PitResp.
6) (PitchIP*3)+(30% of FldgHits)+HR+BB+HBP = PitchPA
7) (70% of ((IP-SO)*3))+(70% of FldgHits)=FldgPA
8) [(1+PitResp)*PitchPA]/[(1+PitResp)*(PitchPA+FldgPA)] = PERmultiplier
9) [(Earned runs)*(PERmultiplier)/PitchIP]/9 = DIERA

Ah, but you're not done there. The big number has to be a 'winning percentage', and to get that you need to perform all the same calculations for his league. But we'll come back to that after you've had some time to digest this.

Reuschel's best season on this measure is 1985. ERA+ agrees but says his second best is 1977. I think I might take a look at 1981 with the Yankees.

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