The name of the sport implies that it's more than just correcting imperfect throws. I think the brushing can curve the stone more than just adding some spin. A

The name of the sport implies that it's more than just correcting imperfect throws. I think the brushing can curve the stone more than just adding some spin. Also, you can brush so other stones move further after collisions. However, I don't see why a "perfect" thrower couldn't beat a world class athlete if they're accurate enough.