Well whether or not you think the underhand serve should be used or not, I had to use it last night. I was down 5-1 to a player I had never lost a set to. I have been having bad shoulder problems lately and it has forced me to reduce my serve to about 30% speed; and even at that, just the motion of the serve causes pain and affects my groundstrokes during the point. But if I don't serve, the groundstrokes are fine. So I was hoping to break his serve like I usually do, but he saw I was hurting and pushed harder than ever and he really made some nice shots to get the lead. Anyhow, I switched to a slightly lighter racquet and continued to play even though I should have probably retired. He's a nice guy and I know it would have meant a great deal to him to beat me so I didn't want to just walk away like that. So I would try the 1st serve normally, but my 2nd serves were all underhand. I won the set 7-5. I'm not happy I had to do that, but it was legal and at least I still got a workout.