Being fair is easy until your friend is on the other team.

Fairness that has never been tested is only an opinion you hold about yourself. It becomes a real trait the first time it runs against someone you want to do well, which is where most people discover that their sense of what just happened bends to fit who they are rooting for. The bending is sincere. It is also wrong.

When a friend is involved, slow down and ask what you would have called from a neutral seat. Say that version out loud even when it stings. You keep the friend more often than you expect, and you keep something else as well.