Someone who washes the hulls before every race doesn't make them win but instead if they are taking the time to do so it means they probably have completed all other preparation...

Take a drag racer for instance... does it make them faster when they have the big truck and trailer painted to match the car, their tool boxes are also painted team colors and they are all wearing matching team jackets? Of course not. But it probably does mean they have exhausted spending money on all of the car stuff that does make them faster.

Someone could prove me wrong and give the example of a person who washes the boat but forgets to cleat the main halyard. I bet overall if you know someone whose boat is spotless, their hardware, lines and sail preparation are also the same.