Comparing sportspeople from different generations is odious, but it's also fun. Killjoys frown on this week's anointing of Serena Williams and Rafael Nadal as all-time greats of tennis - old bean, did you not see Suzanne Lenglen or Fred Perry in full flight? - but what the hell. If sport's not about hot-flushing hyperbole, what is it about?

So here goes. Against her own generation, Serena Williams is one of those athletes, like a Bradman or a Schumacher or a Slater or a Jordan or a Woods, who have a psychological sleeper-hold over their rivals. They only need to turn up and half the battle's won.

Personally, I can't stand the sight of Serena bouncing and grunting around, taking those post-match little-cutie curtseys that spotlight the body dismorphic disorder from which she suffers. The poor girl really does believe people love her. Sad.

As a fan, I'm one of the Anyone But Serena club - Go Olga Whatever-Ova! - but still, as John Howard said, you can't argue with stats, and after a while you just can't scoff at the road kill Serena has left behind over the years.

Martina Hingis preferred to retire. Lindsay Davenport's silky timing went to waste under a command-and-control mechanism that simply turned up its toes when Serena was at the other end of the court. Jennifer Capriati stood up to her admirably, but was at the end of her career when Serena was beginning hers. Justine Henin and Kim Clijsters formed a two-woman Maginot Line but could not sustain it over the long term. And perhaps Serena's greatest achievement has been to eclipse Venus, who enters her twilight years looking decidedly second-rate.

This is what the greatest champions do: they achieve an illusion, making their generation appear a weak one. In doing so, however, they undermine their claims on historical greatness. Is Serena up there with Court, King, Lenglen, Evert, Navratilova, Seles and Graf? It's said that she hasn't beaten much, but hell, all she can do is demolish what's put in front of her. Damn it but she is good.

Doubts about the quality of the opposition don't hold for Rafa.

Roger Federer is often called the greatest of all, but you can't credibly say he's the greatest of his time. In the past five years, whenever Nadal has been fit he has had Federer's measure. By the end of his career he may not win as many slams, and he certainly won't melt the hearts of the all-court aesthetes, but Nadal is straight-out superior to Federer.

He proved it in the 2008 Wimbledon final, and in the following Australian Open final. He proves it in Paris each year. Year in and year out, when both men have been fit and in form, Nadal has won. (By the same logic, you'd have to say Monica Seles was a better player than Steffi Graf. Pre-stabbing, Seles consistently had the measure of the greatest of all time. Until she got knifed, Seles was better than the greatest, so what does that make her?)

So there you have it, shoot me down. Serena Williams deserves her place in the pantheon for breaking weaker spirits, and Rafael Nadal deserves his because he is better than the best. We may not realise it until they're gone, but the 2010 Wimbledon champions are arguably the greatest of all.