When I was in high school I was forced to play football for the first time. I had kept my distance from what I now know is called the culture of masculinity that comes with these sorts of activities. I was bad at it, but that actually didn't matter. I vividly remember an argument about if I had stepped out of bounds. It was obvious that I had: I was staring at my feet, per usual.I said so. There was an insane shock. No one could believe that I would betray my team like that. I had no defense. I was just telling the truth as I had been taught to do from a young age. The thing is, the coach wasn't on my side. He told me I should have kept silent for the sake of my team.
Turns out not everyone is taught to tell the truth from a young age. The culture of masculinity teaches you to lie for the sake of your team. Only winning matters. Now I watch MRAs argue against feminism with the same reasoning. They don't care about honesty. They just want their team to win. I wonder if it's because they were taught that beating the other team is all that matters. That you should do anything you can to win. Just watch the ref. When the ref of common discourse is social norms, it's not going to be a fair game. Not that it should be a game at all.
I played tennis, and since you had to call the other person's ball, and they called your ball, you never wanted to call their ball out when there was any chance it had touched the line, because they would start to make harder calls on your shots. So at some point you learn to call them out when it's obvious, and if it was close enough you call it in. Sometimes you knew the ball was out, but it was a really good shot, and everyone has a better time if you play on (and you wanted them to let your good shots slide).
If we could have tennis-discourse it would be amazing. Maybe the hardest part would be listening to the other person enough to realize that they had hit the ball at all.