40D AF selection suggestions

I've had the 40D less than 24 hours and I am just starting to read up on the AF points and zones. I was hoping someone more experienced could offer me a starting point to begin my experiments in the numerous settings the camera has.

Here is my problem: I'm shooting live action at a professional billiards tournament. Many of the players wear black shirts and things that offer little or no contrast. The only lighting comes from about 4 feet above each pool table. I cannot use a flash at all however I will be using a monopod along with a lot of glass (something around 300 or 500mm). At times I can be closer physically but I would strive to have a few settings programed so that I can easily swing between a shot that is 5-feet away and another that is 50-feet away. Once I identify a shot I want I have about 10-15 seconds before the player has taken up their stance, taken the shot and moved again. Ideally, I would want to capture the image (or multi-shot burst) just before they take the shot, then again once they see how it turned out.

I was planning to just select the central AF point and choose the central focusing region (user manual says this is 9% of the field of view). Then I can go from there once I see what works and what doesn't.

Can anyone offer any other ideas or tips? Like I said, the 40D is brand new and while I have some photography experience this is the first Canon I have ever owned, the first serious SLR I have used, and I am still looking through the user guide.

Thanks.

I think you are wise to use only the centre point for AF.

With such lighting conditions I would think that a long lens (300mm-500mm) would be too slow to get a good image without blur.

Being closer and using a fast lens would probably yield the best results. As for focusing difficulty on dark subjects, you'll have to focus on a point else where (roughly at the same distance) and re-compose.

good luck...

I shoot in these conditions regularly and it's not impossible, just difficult. I am able to use a long lens as long as it's fast.

I just don't have the time to shift the focus to another subject and recompose. I have to fire away with the AF. I average a few good shots out of every 20-25 and over a weekend where I shoot 2000 images I can more than provide enough material for the magazine and their website.

Thanks for reassuring me that the center AF is the way to go.