Congratulate the winner with the same energy you’d want if the scores flipped.

The standard for how to behave after a loss is already in you, because you know precisely what you would have hoped for. Meeting it is hardest exactly when it counts, in the first ten minutes while the disappointment is fresh and your face is doing its own thing. Doing it anyway is not dishonesty. It is choosing which of your reactions gets to act.

Go over, say something specific about what they did well, then move on rather than lingering. Feel the rest of it later and in private. That short walk across the room is remembered long after the result is forgotten.