If you're a professional sportsman, I think you shouldn't drink more than an hour before the game!
Some of my favourite stories regarding beer and sport have to revolve around Bobby Moore. Never heard him described as anything other than a complete gentleman. His biography has a few stories, but the best one is when he didn't come home from the West Ham players Christmas drink and Tina his then wife had to get his mum to go to the pub to make him come home. He left being dragged by the ear and shouting 'but mum I'm the captain of England'