Implement a challenge system, MLB

[bisonlj]

The biggest issue you'll find with replay is it starts to make many of your rules much more technical. Think of how technical a catch/no catch is now in football. You will end up with the same thing on what constitutes possession of a catch by a fielder either on a fly ball or a play like the Detroit game. And I guarantee the force play at second as they turn a double play would become reviewable. Slippery slope.