I think it is time to revist an older article on Mazzone and his effect on pitchers
"When looking at all of the pitchers in the sample, Leo Mazzone's presence lowered a pitcher's ERA by about 0.63 ERA points. To put the effect in perspective, for the average 2004 National League pitcher (4.31 ERA) Leo's impact on earned runs was about the same as Coors Field in the opposite direction. "
All I am saying is the guy can help. Do you hear me Hank?