My pro has a little joke ... "Have you ever heard of the guy who never lost at doubles ... It was his partner's fault!"

While I don't subscribe to that notion, I've encountered some that get dangerously close to that belief ... so here's a nice post from tennis.com on how to select a doubles partner: http://www.tennis.com/yourgame/instructionarticles/doubles/doubles.aspx?id=106270.