A fair coach explains the standard before asking players to accept the decision.

A decision explained afterwards always sounds like a defence, however reasonable it is. When the standard is known beforehand, being left out becomes disappointing rather than unjust, and a player has somewhere to put their effort. Fairness has less to do with the outcome than with whether the rule existed before the result did. Silence lets everyone invent an explanation, and the invented one is usually unkind.

Say what you are selecting for before you select. Use the same words again when you deliver the decision, and be willing to be held to them next time.