Well, maybe I wasn't very accurate. Fact is, the average tennis player is now taller than 80 years ago. One reason might be that people (in developed countries) are generally taller now and thus a guys playing tennis is also more likely to be tall. However, it is a fact, that shorter guys, don't win lots of titles anymore. While I agree that the skills that were important a long time ago, new qualities are now required to be more succesful. And athleticism is probably the most important of them. Small guys often lack the firepower. But they also don't have an footwork and speed advantage over the 185cm guys like Rafa. When was the last time 5'7' won a slam? How many guys that size won slams back in the old days (Laver was 5'7')?