Who's the daddy?

Who's the best grasscourt tennis player in the world?

Easy, Roger Federer.

Really, what about on clay?

Aah, well, Federer is still bloody good, but Rafa Nadal might beat him, that's true.

So, if Federer is best on grass...

No disagreement there, with his Wimbledon record.

...and Nadal is the best on clay,

Without a doubt, unbeaten in 60 odd matches on the red stuff at the moment.

...how can we decide who's best overall?

Aha. Now there's a question. We need some sort of a contest.

Good idea. Do you remember Donovan Bailey?

The hundred metres runner with massive thighs? Yep, what's he got to do with this?

Well, after he won the 100m in Atlanta, and Michael Johnson won the 200m, they had a contest to see who was the best sprinter in the world. To make it, er, fair, they raced indoors over 150m - a rarely contested distance.

Who won that then?

Well, Bailey did, but only after his opponent pulled up. Take a look here and see. Rather spoiled the thing as a contest. Circus is actually the word that comes to mind.

OK, but how do we settle the tennis issue?

I don't know if you'll like this, but I think it's got some legs.

Go on.

How about we build a special court which has clay at one end and grass at the other and have a "battle of the surfaces"?

Oh, for God's sake that's the most ridiculous thing I've ever heard, no-one would go for that in a million years...