Remember those executive toys that were popular in the '80s? You have a steel ball on the end of a thin rod hitting another steel ball that is stationary. As near as we can see, the target ball gets all the momentum of the moving ball, and the moving ball stops dead - close to 100% transfer. But then you have a golfer hitting a ball that is not rigid like a steel ball, but is beefed up by elastic material, rubber or something, to give it a bit of spring. The thing is, if it helps the golf ball get more momentum, how is it that it can't help the steel ball? I mean, you can't get more than 100%, can you?