All the Fastest Men.

For decades, the men's 100-meter final has been the glamour event of the Olympic Games, and the winner takes home bragging rights as the world's fastest man. Perhaps its pre-eminence is due to its simplicity: there's no time for endurance to kick in or midrace tactical adjustments to be made when the whole thing is over in 10 seconds. Which isn't to say a runner's approach doesn't matter. Some sprinters blast out of the blocks, trying to grab an early lead and unnerve opponents. Others build to peak speed and try to maintain it longer than the competition. But what you can't do is ''change your tactics in the middle,'' says Dave Johnson, director of the Penn Relays, one of the premier track-and-field events in the country. ''It's a race of total commitment in terms of strategy.'' Men's 100-meter world record (Usain Bolt, 2009): 9.58 seconds [ABSTRACT FROM AUTHOR]