It's probably not an accident that rapid (as in rapid change) shares a root with rapids (as in Lava Falls in the Grand Canyon). The river guide, piloting his wooden dory, has but one strategy. Get the boat to the end of the river, safely. And he has countless tactics, an understanding of how water and rocks work, and, if you're lucky, experience on this particular river. The thing is, the captain changes his tactics constantly. He never whines. He doesn't stop the boat and say, "wait, no fair, yesterday this rock wasn't like this!" No, the practice of being great…