Every time you see a good script result in a bad movie, a pioneering company lose business to a less innovative competitor, or a genius professor do a poor job of teaching students, you’re seeing a failure of execution. The most brilliant plans in the world won’t help you succeed if you can’t bring them to life. Executing well means that you pick a reasonable direction, move quickly to learn what works and what doesn’t, and make adjustments to get to your desired outcome. Speed matters—a fast runner can take a few wrong turns and still beat a slow runner who knows the shortest path.