Strikes me as a relatively low percentage for a closer, actually. I disagree, since some of those games the Cubs were already losing when he came in. If that were the percentage in actual save situations that would be different. I think he's just saying that in general, it would seem to be a low winning percentage for games in which a given team's closer appears, given that they're coming in with a 9th inning lead the vast majority of the time. The stat struck me the same way.