Sunday, February 6, 2011  Does Clutch Pitching Persist Year-To-
Year? (Part 2)  Part 1 was a couple of weeks ago, when I only
looked at one pair of years. I have now done 5 pairs of years.
Low correlations indicate that pitchers tend not to be clutch
one year and again clutch the next year.  I looked at all
pitchers that had at least 250 plate appearances against
opposing hitters in both of five consecutive two-year periods
both with and without runners on base. There were around 70 such
pitchers in each of the five cases. Data from David Pinto's "Day
by Day Database" which is based on Retrosheet.  I found the
differential between the batting average they allowed with
runners on base (ROB) and the batting average they allowed with
no runners on (NONE). I did the same for Slug%. So if a pitcher
allowed a .240 BA with ROB and a .260 BA with NONE, his
differential was -.020. That means he did better in the clutch
than otherwise.  Did pitchers maintain about the same clutch
performance in each year? Probably not.