Shaunae Miller, Allyson Felix

It appears American track and field fans are outraged by what happened Monday night, when Allyson Felix lost the 400-meter dash on a finish-line dive by Bahamas star Shaunae Miller. When I say "American track and field fans," I am referring to people who watch track and field once every four years, and who break their 47-month runs of apathy to wear their fanatical track and field passions on their sleeves.

Don't get me wrong: I more or less fall into that same category of fan, and I think temporary bouts of passionate insanity are one of reasons the Olympic Games are so much fun. But I'm not about to hurl Twitter insults at Miller for her diving fall at the finish line. The opposite, actually: I just can't get over what a great finish it was from her.

That's because, despite our well-intentioned patriot desire to see Felix snag yet another gold medal in the event she coveted most, what happened to her at the finish line Monday was not illegal, dirty or cheap. It was legal. It was smart. And it was downright impressive.

Shaunae Miller

Miller has said that she actually fell on accident -- that her desire to win a gold and her outright exhaustion thrust her forward onto her face. We have no reason to doubt her. But even if it was done on purpose, it shouldn't be met with anything but admiration.

Miller suffered hard for that gold -- she ran the race of her life, and she left some skin on the track, too. Miller said after the race that she has painful cuts, bruises and friction burns from her fall. That's the primary argument against diving for the finish: You tend to mess yourself up.

Still, it's a gamble that can pay off big time, as Miller showed in the 400 final. And, despite protestations from fans that diving can't possibly be allowed, some cold, hard truth: It totally is. The IAAF rule book, which is the governing document for international track and field, addresses finish-line procedure in this way:

"... the athletes shall be placed in the order in which any part of their bodies (i.e. torso, as distinguished from the head, neck, arms, legs, hands or feet) reaches the vertical plane of the nearer edge of the finish line as defined above."

Allyson Felix

Contrary to some common thought, it isn't your feet that must cross the finish-line first -- if it was, Felix would have won. It's not the hands, either, or even your head. All that matters is getting your torso across the line first, and a head-first dive is a perfectly legal way to do it.

Of course, there's a right way and a wrong way to do it. Diving can backfire, especially if it's done incorrectly. When you fling yourself into the air, your feet are no longer able to drive you forward, which means your body loses velocity with every inch you travel. If you dive too early, you might actually slow yourself down at the finish line, costing you a higher-place finish.

But the immediate motion of diving can provide a quick acceleration, assuming your muscles have enough left in the tank to propel you forward. According to Miller's account, her finish was more of a collapsing forward than an intentional dive, but a perfectly well-timed collapse at that.

If it had come just a step earlier, she might have slowed down too much before hitting the finish line, which would have given Felix a window of opportunity to slip back in front for the gold. The timing is so tricky that most runners are content to just lean when they hit the finish line.

That's the one odd thing about Felix's finish: She didn't lean, and doing so might have been enough to stave off Miller's dive. It's possible she wrongly assumed she had locked up the win. But for most sprinters, a finish-line lean is its own form of insurance, and a better strategy than going for the dive:

While the merits of diving might be debated, one fact is unassailable: It happens all the time. I started putting together a list of every major track race that featured a decisive finish-line dive, but it quickly became an overwhelming task. Just trust me when I say: It's not that uncommon. In fact, it's far more ordinary than the casual fan might realize.

More odd, I would wager, is the occurrence of a major track and field championship meet that doesn't feature at least one finish-line dive.

We know of Miller's dive to beat Felix for the gold, but don't forget that earlier this summer, at the U.S. Olympic Trials, Felix missed out on a spot in the 200-meter dash after losing to fellow American Jenna Prandini. Prandini, who was nursing a sore ankle at the time, edged Felix with a dive at the finish. That one, too, was unintentional. But the results are the same: Felix failed to qualify in that event.

Shaunae Miller

A dive also determined the final spot in the women's 1,500 at this year's U.S. Olympic Trials. And at the 2012 U.S. Olympic Trials, Jeff Porter dove past two other competitors to snag third place in the 110 hurdles, earning himself a spot on the Olympic team.

Those are just the success stories. There are failures, too, which underscore the risk that comes with diving at the line, intentional or not. And those failures only offer more reason to celebrate successful dives as adrenaline-packed finish-line moves that inject the race with excitement and add another layer of complexity to the race.

According to The Wall Street Journal, there's a chance the IAAF technical committee will discuss possible rule changes to address diving at the end of races. But diving has always been allowed, and there's no imminent threat of that changing.

In the meantime, U.S. fans upset at Miller's diving win should look farther back into history before getting all hot and bothered. At the 2008 Olympic Games, American runner David Neville was in fourth place when he dove at the finish line of the men's 400 final.

Neville's dive was intentional. And it worked: He stole third place right at the end, earning himself a bronze medal.

It would be a huge mistake to overlook the identity of the man Neville beat for bronze. His name was Chris Brown, representing ... The Bahamas.

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