The Reds are 7-7 when Scott Rolen plays this year. They’re 1-4 when he’s out.
They were 27-13 in his games last year, after the trade. In the 20 games Rolen missed after joining the Reds, they were 6-14.
So, in Rolen’s three months, the Reds are 30-24 (.556) with him, 7-25 (.213) without him. He’s played well, to be sure, but no player in history – not Babe Ruth, Ted Williams, or even Juan Castro makes the difference between a 90-win team and a 35-win team (the two records extrapolated to a full season).