This is applicable for either a parent or a coach. It comes from the Mahaney Sports podcast (CJ & Chad). Chad asks CJ this question at about the 6:44 mark if you’re interested in listening to the whole thing. Below are some excerpts (these are all things CJ said, as a parent, that he wanted to say to his son, Chad):
After a game, what a parent/coach celebrates is what a child emulates.
I wanted to celebrate displays of character more than displays of skill or victory
We believe in playing to win the game but ultimately that is not why the Christian plays
As a parent, I wanted to draw attention to your demeanor as you played.
When you scored a goal [in soccer], I watched to see if you thanked/congratulated teammates rather than drawing attention to yourself.
How did you rejoice when another teammate scored a goal?
Were you gracious to the other team?
What do you think about these thoughts? What would you add to them with regard to what you would say to your child after the game?