Don Ehrke of Dugout Central looks at the question “Does putting on a Yankee uniform still make a man a better player?
Looking at “at every significant performer (minimum 200 at bats or 60 innings pitched) who joined the Yankees from another team between 1997 and 2007,” Don concludes:
Overall, 45 significant players joined the New York Yankees between 1997 and 2007, and surprisingly, 25 didn’t play as well in the Bronx as they had with their previous team.
And, who was the G.M. of the Yankees during almost all of this time period?
The biggest problem found in the study was pitching. As Don wrote:
Twenty-four pitchers joined the Yankee staff from a different club and pitched 60 innings or more. Nine pitchers improved their ERA plus while 15 declined. Among pitchers who performed better in New York the average improvement in ERA plus was 24 points, while the average decrease among those who performed worse was 56 points (excluding Chris Hammond – an extreme statistical outlier).
And, that didn’t include Kei Igawa. Ouch.