I don't think acting like adults is superficial. You can be competitive without the unwritten rules being necessary. I think that's really the crux of the disagreement. And I'm more than a bit baffled that you think competitiveness requires this. Or that rivalries require it. Really, all the unwritten rules do is offer shade to overly sensitive players that want to enact revenge. And if you want to be overly sensitive in any job and enact revenge, you could. It's just most of us don't, because laws prevent us from doing it and basic decorum. Baseball allows it to operate because, for whatever reason, trying to hurt someone else is ok. It doesn't have to be. I played football and hockey, I had rivalries, I was competitive, and never once did I feel I had to intentionally try to hurt the other player in order to stay competitive.