Thursday, July 17, 2008

The Zo Spin Zone

From Todd Zolecki's blog regarding the Joe Blanton deal (which reads a lot like an employee of the Phillies wrote):

Take away his four worst starts this season and he has a 3.58 ERA,

This is what we refer to as "cherrypicking". When you have a sample size of 200 starts, maybe you can point to four starts as an aberration. When you have a sample size of 20 starts, pulling out four starts equates to 20% of Blanton's performance. Would you justify a batter's first half performance by removing 60 at bats? Of course not. So why do it with a pitcher?

But if you're going to play this game, you can look at it from a lot of different angles.

Take away Joe Blanton's four best starts this season and he has a 5.82 ERA.

Take away Adam Eaton's four worst starts this season and he has a 4.15 ERA.

Take away Cole Hamels' four worst starts this season and he has a 2.10 ERA.

THIS IS WHY YOU DON'T REMOVE 20% OF YOUR SAMPLE SIZE.

I liked the pun I used for the title.

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