Meh. I don't compete all that much, but if I get in practice ahead of time, I do just fine.
I think it's all about attention to detail when watching pro matches, and what's going on in your head when you are practicing.
When watching pro matches, you need to be looking for the common shots that come up, and know enough about your stroke/knowledge to know whether you have them down cold, or not. If not, practice them. Set up drills surrounding that specific shot. Write down/diagram them so you won't forget.
And when practicing, I feel you DO need to have a certain amount of aggression in your mindset whilst practicing. The practicing has to be PREPARATION for something. It has to be about what you are gonna do to the other guy when you finally face him. Depending on the game, this will take many forms. For example:
9-Ball - Practicing thousands of 9-ball breaks where you squat the CB perfectly and drive the 1 ball down table hard enough to bounce back off the end rail for an easy start. Playing safe off a 1 ball on the end rail over and over in case you come up slightly short on the proper break speed.
One Pocket... Practice getting EVERY possible ball you can, even going past 8. If you prove to yourself you can run 14 (my high run) or 15 balls in One Pocket, you're not so worried about giving up a ball or two to keep your opponent off a shot. Practice two railers at all distances back to your pocket... Practice thin cut behind-the-stack banks over to your hole when it's a definite sellout if you miss, but a definite win if you make. (You have to intentionally think of it as a sellout shot if you miss, even if you are practicing, to help you find the best "make" speed)
8-Ball... Practicing last pocket 8 ball as a means of pushing your performance in what is a relatively easy game if your break is on point. This additionally trains your thinking to really bear down on finding the right pattern and managing the 2-3 balls before the 8 correctly.
Then again, before playing any big tourney, I also do general focus exercises like picking a very small point on the wall 20-30 feet away and intently focusing on it for as long as possible, attempting to prevent my eyes from drifting. I have found that when at the table, if I focus as intently as possible on the most minute contact point I can imagine on the OB, and keep my focus there throughout the whole shot process, not only do I make the ball more often, but this prolonged intense focus has a zen-like effect that drops me into dead stroke at will.. It takes a LOT of focus exercise to be consistently usable, though.
So... I think the aggression/dick measuring to a certain extent must be there in practice, and if it is, then it can be almost as effective as competition. I think a lot of people practice just for the pure joy of hitting ball and pushing their capabilities, but they are missing the war-like nature of practice.
Practice, to be most effective, should be akin to a soldier practicing disemboweling their opponent with a bayonet. It has to be forceful, attempting to push the bayonet completely out the other side of the practice bag. That visual/mental imagery MUST be there to get the most out of the practice. If done with correct mental imagery, the real thing will just be a matter of muscle memory.
Short Bus Russ
Just think how much better you'd do if you competed more.
Lou Figueroa