Some have said "sport develops character", but perhaps more accurately "sports reveals character". I am a former player (of many team sports), a coach, a referee, and most recently a parent of a son who plays sports. I have sat in almost every seat to watch a game and I have experienced the emotions that are drawn out by a game. In recent years the news has covered stories of parents getting too involved during or after their child's game and altercations taking place. There have even been occasions of people going to jail for something they did. Now in most hockey arenas, and increasingly in other sports facilities, signs are on the wall instructing parents how to act. They are to show officials respect, remember coaches are volunteers, and that the players are children. But the message cannot be said loud enough to effect change in everyone because sport reveals character. A sign will not change who someone is inside. It might prevent how they act on the outside, for a time, but who someone truly is will ultimately be revealed. That said, sports can develop character and hopefully the children have a chance although many of their parents seemed to have missed theirs.
Romans 5.3-4 "Not only so, but we also glory in our sufferings, because we know that suffering produces perseverance; perseverance, character; and character, hope."