In coachspeak, which is sometimes like English, the term "tournament tough" often arises. It has little to do with tournaments and everything to do with toughness.
I've always thought it meant to prepare as well as possible for a situation, and then trust that preparation to get you through. In tennis it means simply getting to a level where you have confidence in your shots, and then going into a match and hitting those shots with the same confidence.
Easy.
But it's not.
It isn't easy because unlike a formal match, there's no penalty for missing in practice. There should be. I could inflict it upon you—ten laps if you miss an easy forehand!...but that wouldn't help your forehand. It's your reaction to mistakes that tells me what you're like as a tennis player.
This may be a tough pill to swallow, but swallow it now and start to feel better:
IF YOU LAUGH OFF TERRIBLE SHOTS IN PRACTICE AND AGONIZE OVER THEM IN A MATCH, YOU'RE NOT A TENNIS PLAYER.
You may have some athletic skills—maybe more than other players'—and you may even use them to play tennis, but you're not tournament tough, and if you aren't tournament tough, why are you here? You could be playing tennis with your friends on a Saturday morning. Casual. Fun. No pressure. Dunkin' after. Or Starbucks. But you chose to put yourself out there, to challenge yourself. Now...complete the process.
I'm paraphrasing the humorous illogic of a mid-twentieth century baseball player, but there's some truth to it. Tournament toughness means having control over your game, over the possibility of failure. It's knowing that if you go out there and play every instant at peak level, you won't be distraught or angry or bitter after a loss. You'll feel good because you played well—because you left everything on the court.
Tournament toughness: it's the reason why, when evenly matched teams meet, one wins and the other doesn't. We don't want to be the one that doesn't.