This is precisely my point, which is that the athlete's state of mind has much more to do with their performance than their equipment does (unless it's complete

This is precisely my point, which is that the athlete's state of mind has much more to do with their performance than their equipment does (unless it's completely malfunctioned, of course). Put 30 other athletes and coaches and so on in the mix and you have a total mess. Even if the markings made a positive difference it would likely be so small you couldn't distinguish it from the noise.