Racking Balls
In the history of pool, it seems that more creative energy has been given to ways to rack the balls consistently tight than any other aspect of the game. Remember the Sardo rack? Now there was a Rube Goldberg contraption if ever there was one. And what about the Laser Rack? That attempted to solve the problem with getting the rack straight, but didn't do anything about getting a tight rack. And of course the Delta-13 aluminum rack is a great product; it produces a more consistently tight rack than anything else I've used so far.