9Pivots and Power Strokes

Imagine canoeing down a bubbling brook with a couple of pals. The fresh autumn breeze soothes your throat and cools your face. You quietly take in the sights of freshly fallen leaves painting the riverbanks in stunning shades of orange, red, and yellow.

Then suddenly you float around a bend and spot a fork in the river. The right branch of the fork leads to another tranquil stretch of stream. But that's not where you're headed. You are drifting toward the left fork. Your pupils balloon as you watch the river's powerful current thrust you ever closer to a swirling, foaming, Class 5 rapids.

What do you do?

The instinctive reaction is to start making what are called “power strokes” on the left side of the boat, which is basically just river-rafting jargon for paddling like your life (or at least your dryness) depends on it. Thanks to your frenzied power stroking on the left side of the boat, your wobbly vessel mercifully begins to angle toward the right.

But it is a painfully long and wide arc of a turn. Those power strokes are a catch-22. The harder and more forcefully you paddle to make the turn in time, the faster you hurl your boat downstream closer and closer to the dangerous fork ahead. At this point, you are doing as much praying as you are paddling, and then.…

Whoa. That was close. You made it just before things got ugly.

But the trip is far from over. And now you know that this river has some gnarly sets of rapids, and the one you just avoided ...

Get Domino now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.