Warning: bragging below!
I have coached competitive youth basketball for several years. I never played team basketball growing up and took up the sport in my late 30s.
My daughter plays on the high school team and I am proud that I have coached many girls who on are the local high schools teams. Some of the boys I have coached are also on the high schools teams. I have earned a couple of "Coach of the Year" awards. At least in basketball, most (but not all) parents like me, the refs like me, the other coaches like me, most (but not all) the players like me. And more importantly, my kids like me and beg me to coach their teams because they have been on teams with other coaches (I cannot coach both kids at the same time).
As a coach and parent, I am a yeller. I do not sit quietly on the sidelines. But I am never yelling negative comments. It's always, "Great assist!", "Good pass!", "Awesome rebound", "You made that play happen". I get e-mails from parents thanking me for being so positive. I will take a kid out of the game to talk to them on the bench if I see something I don't like, but I will not yell at them while playing.
But if you are parent yelling negative things like, "C'mon, work harder" or "Block your man next time", then I am going to be talking to you. The kids are working hard. The kids are not slackers. It's hard work to get out and play.
My kids play soccer, baseball, and football as well. I do not coach those, but I usually work as a photographer and sometimes assist the coach. If you are yelling, "Don't strike out this time", then I am going to be talking to you. If you are the coach, then I am really going to be talking to you. Good yells, are "Great pass!" "Great cross!", "Nice assist!". If you are not yelling encouraging things, then why bother to go to the games? Don't be one of those lumpy parents on the sidelines.
I realize that children play sports for different reasons: to be with friends, to have fun, they are good at it, to try something out, or their parents make them play. I like to see teamwork and fun. If you are a ball hog, you will not get drafted to my team. My team won't have the top couple of players in the league, but we will have a bunch right after those kids. We always have the most assists of any team in our division.
I also like to see improvement in skills. I can make just about anybody a better basketball player if they come to practice. I realize that most kids will not practice at all on their own, so get your kids to practice early.
OK, that's what kind of sports dad I am.