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1. WE'VE GOT THE TOUCH … Plastic touchpads outfitted with sensitive pressure switches have been vital to automatic electronic timing in swimming pool racing since the 1968 Games in Mexico City. The pads connect to an electronic console capable of timing to 1/10,000th of a second, but official times are only recorded to 1/100th of a second due to imperfections in pool dimensions.

2. … BUT THERE'S ALWAYS A BACKUP PLAN. Should the touchpads fail, three judges on each lane control a separate console that can register final times (the middle time of the three is taken). They face the same challenge as in stopwatch days—trying to catch the moment of contact amidst waves and spray—but have the benefit of high-speed video cameras over each lane for additional support.

3. IT GETS PRETTY TRICKY DURING RELAYS. Because the touchpads are so sensitive, they are now automatically armed only during a pre-set window of time in which swimmers are expected to touch the wall. This prevents any false times being recorded should a teammate accidentally hit the pad on his way out of the pool.

4. PUT … THE GUN … DOWN &hellip Swimmers no longer listen for a starting pistol. Now, there are horns installed inside each starting block, which counteract the 1/10th second it takes for the sound of a pistol to reach the swimmers farthest from the starter.

5. WATCH YOUR STEP! Starting blocks are wired to sense the slightest pressure changes, so it's possible now to know when a swimmer even tenses to start. As a result, it's now being debated as to whether or not false starts should be based on premature tensing pressures in anticipation of a start, even if the swimmer departs the block after the starting signal.

Alex Cheng is the author of Splitting the Second—My Wacky Business in Olympic and Sports Timing, which chronicles his eight years as president of Seagull, Inc., exclusive agents for Omega Electronics.