Suzanne F. Boswell

First, the basics: a triple double = a double back flip with three twists. Wow! That sounds super-hard. But if you don't know gymnastics, what does any of that really mean? Let's break it down further...pic.twitter.com/Kzivn8EbA6

Here is Gabby Douglas performing a single back flip - one flip in the air, in the tucked position. The back flip is a fairly easy skill on floor for elite gymnasts. It's worth an A, or .1 points in difficulty.pic.twitter.com/xWPDsycCBF

Sometime around the 1976 olympics, women's gymnasts started doing the double back (two flips in the air, in a tucked position). Here it is, performed by Sarah Finnegan. It's worth a D in elite gymnastics, or .4 points in difficulty.pic.twitter.com/WdPxZdSUxS

In 1978, Elena Mukhina brought out the full-twisting double tuck - a double tuck with a full twist. Here's Biles' version of the Mukhina: she does a full twist on the first flip, and then a "regular" back flip at the end.pic.twitter.com/RQc7lYx2uY

Here's another view at the full-twisting double back, this time from Larisa Iordache. Again, Iordache twists during the first flip, then does a regular back flip at the end. This skill is worth an E, or .5 points in difficulty.pic.twitter.com/jkMzzejkE6

In the late 1980s, gymnasts were like "but what if we did a double DOUBLE." because it was the eighties, and people were wild. The double double means two back flips, and a twist on each back flip (two twists). Here's Biles performing the double double.pic.twitter.com/TLnCgsilrL

The double double was named after Daniela Silivas in 1988. Here's another look at it, from Morgan Hurd (2017 All Around World Champion and personal hero). Watch how she twists on both back flips: The Silivas is worth an H, or .8 points in difficulty.pic.twitter.com/LMx3PHdOwA

The TRIPLE double means three twists, two back flips. Which means Biles is doing more twists than she has back flips to do them on. Now, I could be wrong, but I think Biles accomplishes this by doing two twists on the first flip and "just" one on the end.pic.twitter.com/MZJ1MtIQiT

But here's what you should notice. The double double was named in 1988. Adding the first twist to a double back took a couple years. Adding the second took ten. Adding the third twist took 31. And Simone Biles.pic.twitter.com/a2iv21oy6S

Which isn't to say there hasn't been innovation in the difficulty department. In the late 80s, early 90s, we had the full twisting double layout (a double back in the stretched position, with a full twist) (Which Simone can do beautifully, of course).pic.twitter.com/ZhW0n97qro

Then Biles was like "what if I did a double layout with a HALF twist" (2013), and everyone was like "we didn't know you could do that?" (double back flip, stretched position, half twist - worth a G, or .7 points)pic.twitter.com/yEi6Gf7EYI

And in 2013, Victoria Moors said "what if you did a double layout with two twists" and everyone was like "what if you didn't die?" And now the "Moors" as it's know, is just a more and more common skill - see Jade Carey performing the Moors, below (I-rating, .9 points).pic.twitter.com/2jTGTP0GCe

But the triple double remained elusive. Until gym fans saw Biles throw it in practice videos, and in podium training.pic.twitter.com/d8jxMQOHCs

IF Biles successfully performs the triple double at World Championships, it will be either the third or fourth skill named after her in the Code of Points, after the Biles on floor (double layout with a half twist) and the Biles on vault (a yurchenko half-on, two twists off).pic.twitter.com/gtlyauIZLx

Usually, gymnastics fans get pissed if you compare men and women's floor skills, because women dance and men don't, women do dance skills (leaps and turns) and men don't. (I personally would like to see more attitude turns in men's artistic gymnastics, but no one asked me)pic.twitter.com/Vi1jE0tu0v

Kenzo Shirai is one of the best, if not the best floor worker of this generation - he's created 3 new floor skills and debuted multiple floor combinations. Like Biles, he's the only person who can perform *his* floor routine (everyone else would die). Here's his triple double.pic.twitter.com/gLzLxyVUAS

Shirai does a great triple double (no shade, I love him). But here's another angle where you can really see the difference with Biles. Look at the shape of the Shirai's tuck in the air. You want the tuck to be as compact as possible.pic.twitter.com/Ov0ZpiBlAo

Biles is known for having an excellent tuck shape - the angles of her hips and knees are at close to 90 degree. She's practically a drawing from the Code of Points.pic.twitter.com/Q0B3avnnDE

Compare these two stills of Biles and Shirai in the air (near the end of the second flip). Note how Shirai's knees and hips are much looser than 90 degrees. He's almost straight up and down.pic.twitter.com/RxYO6m98VD

Biles, on the other hand, still looks like she's in a tight tuck shape near the end of the second flip. Her knees are tighter than 90 degrees, and her hips are pretty close to a 90 degree angle with her legs.pic.twitter.com/6fr4wQoSS9

Biles also LANDS with her chest higher: Shirai lands a little low, with knees pretty bent and chest almost at at a 90 degree angle with his hips.pic.twitter.com/MOlmtJnIcJ

Compare Shirai's position with where Biles lands - with her chest nearly at a standing position, knees lightly bent. This high landing position means Biles completed the move with time to spare.pic.twitter.com/Tcb7amwYnZ

(By the way, I did pick the best men's triple double I could find, and this isn't to throw any shade at Shirai, who is one of my two or three favorite men's gymnasts. Have Kenzo Shirai sticking a quad twist, one of his eponymous skills, for fun.pic.twitter.com/0r60iTVl94