Trying to think of an example in 'physical' sports (give me some rope here)... in baseball you start by using light aluminum bats, then in college they impose w

Trying to think of an example in 'physical' sports (give me some rope here)... in baseball you start by using light aluminum bats, then in college they impose weight rules on non-wood bats, then in the MLB they impose weight rules on wood bats. However, pro players sometimes train with non-regulation bats to work on bat speed or for pregame warm up. Rarely, a training bat will accidentally get used during a game. If such a bat breaks during the game, it will reveal itself as a hollowed or corked bat. The consequences, esp with regard to public perception, for such mistakes are severe. https://fanbuzz.com/mlb/sammy-sosa-corked-bat/ https://fanbuzz.com/mlb/sammy-sosa-corked-bat/