thanks.
something else that might be helpful is that i reckon playing one more effort level than your opponent (if they on similar enthusiasm to you) could turn a game that you would otherwise lose by 10-20 points to one that looks a lot more level (say within 5 points) by the end of the game. obviously when things get close at the end of the game anything can happen with free throws, fouls etc.
its not a % but with experience you can normally call the difference between you and your opponent with some scouting and educated guesses.