Anyway, your kid will not understand why you were screaming. He will understand that you were whining, giving him permission to do the same. Attend games AND practices. Youth sports are not synonymous with baby-sitting. Do not drop off your kid two hours before batting practice and make the coach wait in the parking lot afterward until you decide to show up.
Youth sports are about learning fundamentals, teamwork, sportsmanship and eating candy.
They're not after-dinner day care with a scoreboard. Form a relationship with the coach. Doing so will not guarantee your kid is first-line center in hockey, batting cleanup in baseball or playing quarterback in football. It will help you understand the coach's philosophy about playing time, positions and safety. And you just might learn something.