Every Olympics produces at least a couple of nail-biting finishes, races so close we yell ourselves hoarse screaming at the television, as if that would push the athletes just a little bit harder.

The Games are like that. The very best athletes in the world push themselves beyond anything we can comprehend in races decided by hundredths of a second or fractions of an inch. Who can forget the breathtaking finish of the men’s 100-meter butterfly in Beijing, where Michael Phelps beat Milorad Cavic by a mere 4.7 millimeters? Moments like that are why we tune in.

The job of measuring finishes that close falls to the Olympic timers, a team of 450 technicians who use more than 400 tons of equipment to ensure peerless accuracy timing. But sometimes even the very finest in timing technology is not enough, as we saw during the women’s 100-meters trials in June, when Jeneba Tarmoh finished in a dead heat against Allyson Felix.

Dead heats are rare, but not unheard of, as we saw during the 1984 Summer Games when Nancy Hogshead and Carrie Steinseifer registered the same time in the 100-meter freestyle. Both won gold, the first double-gold in swimming history. Close finishes are what give the Games their excitement.

Here, straight from The Book of Olympic Lists: A Treasure-Trove of 116 Years of Olympic Trivia (Arum Press, $14.95) by David Wallechinsky and Jaime Loucky, are 10 incredibly close Olympic finishes.