Tuesday, April 17, 2007

More Meaningless Baseball Stats

If you are merely a passive observer of baseball, you may look at the current records of the Orioles and Nationals and deduce that they are on pace for x wins and x losses based on their winning percentage 13 games into the season:

Orioles: 7-6, .538 winning %, on pace for an 87-75 season (gotta love April).

Nationals: 4-9, .308 winning %, on pace for a 50-112 season (not loving April as much).

But if you use Bill James' pythagorean expectation formula -- 1/(1 + (Runs Allowed/Runs Scored)^2) -- you get different results:

Orioles: 60 runs for, 57 runs against, pythagorean expectation of .526 winning %.
Bill James would say 7-6 is right where they should be, and stretched over an entire season they would go 85-77.

Nationals: 36 runs for, 67 runs against, pythagorean expectation of .289 winning %.
James would again be satisfied with their 4-9 result, and it would stretch out to 47-115 if they continue to play like this.

So not a huge stretch in either direction, but it's interesting that even after only 13 games, Bill James' stats -- which were meant to be applied to full seasons -- are proving accurate.

If I don't get lazy I'll keep track of this throughout the season.

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