Baseball has stats for everything else. How about "most homeruns hit against your former team the first game after being traded"?

Choo probably finishes 2nd.

First (that I know of) was Dick Williams, who later won 2 or 3 World Series managing the A's. In midseason of 1957, he was traded from the Orioles to the Tribe.

And, of course, they were playing each other. So in his first game, Williams - who had 7 homeruns for the whole season - hit 2 homers against the Orioles.

He didn't do anything the rest of the year, but he sure made a great first impression. He was traded again after the season.

Hopefully, Choo gives a better return long-term.