In 2008 and 2009 I have watched several of John McEnroe's matches on the senior tour. He has identical serve stroke as he did 25 years ago. Everything about his serve stroke is identical (preparation, stance, ball bounce, toss stroke, follow through, etc). Even some sports announcers mentioned in amazement. One of the stations showed a split screen showing McEnroe's serve today as compared a match in the early 1980's. The only difference is that he has slightly less power behind the ball. Placement is still there though.