In defeat: If the opponent’s hand is raised. Blame no one, for there needn’t be blame. You put in your effort during and up to this point, the rest is out of your hands. Be thankful for the opportunity, and respectful of your opponent’s hard effort before and during their contest against you. They were on the same mat at that moment. Be thankful for his willingness to put himself in the same position as yourself, where only one can win today, in front of everyone, and one must lose. Cherish his courage that matches your own. Ignore the shallow comments of the bleacher peasants and on-line warriors, they are spectators and you’re the sportsman. Be proud, take credit for all the hard work and planning you put into the weeks leading up to this moment.
In victory: take the moment to absorb what happened, record it for later review, take pride in being there, shake hands, acknowledge their skill. Don’t run around like an idiot… beating your chest, digging them an air grave, flipping them off or throwing your mouthguard. No dropping to your knees, pointing to and thanking the gymnasium ceiling. Shake their coaches hand, walk off and recharge. Avoid the temptation afterwards to gush over details of your victory, especially to someone who has just lost. A person can be judged better by how they handle victory than by their ability to achieve it, because the former is all them.
Would an outside observer be able to tell if you won or lost, if no hand was raised, based only on your immediate post-match behavior? The goal is no.