[Jack of Arcades]

[ QUOTE ]
"Leo Mazzone is worth .55 to .85 runs per game."

So why, then, would the Braves have given permission to the Yankees and Orioles to talk to him?

How do you come up with .55 to.85 rpg?

[/ QUOTE ]

JC Bradbury compared pitchers pre-/post-mazzone and during the mazzone years and found that, on average, he lowered their ERAs by about half a run.

Of course, it's really hard to get a good read on it with other things affecting ERA (park, defense) but nobody else showed any significant result.