You see this in competitive dinghy racing. One person will intentionally starve their competitor of good air, so they know and could do the opposite if they wan

You see this in competitive dinghy racing. One person will intentionally starve their competitor of good air, so they know and could do the opposite if they wanted. Lots of sports deal with this “dirty air” concept like Formula 1 especially, regulations were changed for this season so the car in front produces cleaner air off the back so cars behind can follow better (which provides a better chance to overtake/better viewing spectacle).