Disclaimer: The .65s Theorem does not guarantee that a dub attempt at around .65s will be successful. You should have the aerial awareness and decent twisting technique before you attempt your first dub on any surface. HOWEVER, if you have a decent dub already under your belt and are hunting new dubs or new dub set-ups, the theorem will give you a pretty good estimation of whether or not you are ready to make an attempt.
Definitions:
In-Air Time (IAT): Total time between the last jumping foot leaving the surface and the first landing foot entering the surface (single leg landing) or both feet entering the surface (stomp landing).
Skill-Completion Time (SCT): Total time between the last jumping foot leaving the floor and having completed all flipping and twisting rotation, ready to land.
Surface Time (ST): Total time between the first foot entering a surface and the last foot leaving the surface.
Dub: Double-twisting variation of a base single-twisting skill
The Query
Wouldn’t it be great if you knew exactly how high you needed to be to finish a certain skill? How about a checkbox as a coach that would let you know whether or not your athlete is ready to take a new skill to the floor? With a lot of skills in tricking there isn’t really a magic number to hit for height or airtime. It simply doesn’t apply. A lot of tricks do not directly translate to each other and even then, you can often compensate for lack of height by spinning or flipping really really fast.
The Exception
For some odd reason, dubs point to a fairly consistent in-air time requirement. Through sheer chance of playing around on the coach’s eye app and a random instagram downloader, I’ve come across the phenomenon I will refer to as The .65s Conjecture, which lead to The .65s Theorem and the Surface-to-Surface Corollary. First, lets look at a widely used metric in the realm of trampoline gymnastics.
Trampoline Gymnastics: The 10-bounce Time
As a Trampoline Gymnastics coach, a useful metric in determining how “high” a gymnast jumps is the 10-bounce time. Basically a gymnast will jump as high as they can and signal they are ready for a coach or fellow athlete to time how long 10 bounces take. The gist is that a higher bounce time directly infers more in-air time which usually equates to more height.
A 10-Skill routine will likewise be timed and measured against a 10-bounce time to track efficiency. If a trampolinist has a 10-bounce time of ~ 19s, and a 10 skill routine of 16s, he is not making good use of his height or power. Compare against a similar trampolinist with a 10-bounce time of ~ 18s with a 10-skill routine of 17s.
As a training tool, it is great to track progress and to have an objective measurement of height in skills. Athletes will strive to increase their 10-bounce time and 10-skill routine time—and therefore their height.
Can we have a similar metric to help our tricking? With the 10-bounce time which is on scale of ~10-25s hand-held stopwatches work well enough, but that could not possibly work for tricks which rarely exceed a full second. In addition, the 10-bounce time encompasses IAT as well the trampoline surface time.
This is fine on trampoline, as a the trampolinist’s surface time is fairly consistent among athletes of a similar mass. On the floor however, surface times can vary to a significant degree between athletes of varying elasticity as well as from take-off to take-off! Think of punch full vs pop full. The pops will by nature spend more time on the floor, but the punch full will likely have more in-air time.
Average time, especially based on reaction time of a timer, cannot be an effective measurement for tricking height.
The Digital Stopwatch
Basically through the wonder of technology, we have an android and IOS app that can serve as a very precise digital stopwatch for single skills. You can use whatever app you want to do this, as long as you can accurately mark the exact moment when your last foot leaves the floor and the exact moment when your landing foot/feet enter the floor. Shall we look at a few examples?
Kerwood’s ch7 twist clocks in at .55s of In-Air Time
Kerwood again, Wrap dub: .60s, Cork dub: .65s
Couple dub dub dub examples all ~ .65s
Morehart’s dub A clocks in at .60s
Cali rolls just over .65s from both Rikku and Vellu
Floaty Dub B from Brenden makes .65s while the jank Dub b from myself just gets to .60s
Kai hitting standing dub dub ~.65s
Tak dub from Towels reaches just about .62s
The .65s Conjecture
Dubs from any setup take approximately ~.65s of In-Air Time to complete flipping and twisting rotation.
Variance
Less than Dub
Cheat 720 twist: ~.56
Dubs w/ ~ 1.5x or more twisting rotation:
Rudi (front 1.5) ~.60
Dub A ~.60
Dub B ~.60
Cart dub ~.60
Wrap dub ~.60
tak dub ~.60
Back 1.5 ~.60
Dubs w/ ~ 2x or more twisting rotation:
Back dub full (punch, etc): ~.65
Pop dub (scoot, etc): ~.65
Standing dub ~.65
cork dub ~.65
Kack roll (Cheat 1080 twist): ~.65
Cheat 12: ~.65
Okay now that we are sufficiently convinced that dubs take ~.65s to finish flipping and twisting, we can then make the assumption:
You should have around .65s of In-air time on any given dub attempt.
The .65s Theorem
Your In-Air Time should consistently be ~.65s for any single-twisting skill you are trying to dub.
No matter what kind of set-up you use, what surface you’re on, or what kind of single-twisting skill you do, you will need ~.65s of IAT in order to make a decent attempt at the dub. Hooray, quick and easy way to measure how close you are.
2019 Update: Shosei Iwamoto dubx5!
There have been quite a few questions on Shosei and the younger Japanese twisters who appear to be twisting at supersonic speeds!
It does seem that trickers twisting fast do require less in-air time from watching them. However, with Shosei averaging ~.62-.63s the difference is ~.02s to our other examples of people.
What we do find is that Shosei is totally twisting fast. But his in-air time is mostly the same. What we get instead, is a faster eagle open up on his dub swings, which probably relates to better control into the next swing.
The Surface-to-Surface Corollary
Although a lot of dubs take ~0.65s to sufficiently complete flipping and twisting rotation, no such general rule applies for singles, triples, etc. What a bummer that the digital stopwatch can’t help us with anything other than dubs. Or can they?
If we recall that in-air time accounts for only time in the air, why wouldn’t skills on trampoline, fast track, air track, etc translate to floor skills? In this way, rather than a specific rule like the 0.65s theorem, you can measure how much time it takes to complete any skill (SCT) on an easier surface against how much In-Air Time (IAT) you have in your timers to determine your readiness. The Surface-to-Surface (S2S) Corollary is as follows:
To be sufficiently ready to translate a skill from one surface to another, you should be able to complete your skill on the easier surface with a SCT less than or equivalent to an IAT that you can achieve on the harder surface.
Right. Here’s a couple example’s for triples, which I’ve measured to be roughly between .70s and .90s on the floor depending on what kind of height/twist ratio you use.
Skill Completion Time on Trampoline / In-Air Time of timers on plyo / Ready to translate?
.75/.80/Y
.85/.85/Y
.90/.87/N
So if your IAT on the floor is equal to or higher than your SCT on the floor, you should be ready to make a decent attempt safely. Great, good to go! What about if you fall within the “no” category?
If your tramp trips take .90s to complete, and your highest fulls and dubs have .87s of IAT, you aren’t quite ready, but you can either train your tramp trips to finish sooner (twisting/flipping faster) or you can train your plyo fulls and dubs to have more in air time (get higher) or better yet both.
Again this can be useful knowledge to apply for translating skills between training surfaces, and especially for a tricking coach to give a green light on an advanced skill.
Mercenary Tricking 