hey Geoff, i forgot a part. make sure you also take notice of which direction Jon & Steve twist their front tumbling. then look at their vaults.
so, the round off. from the root skill cartwheel. and it is still a left cartwheel. remember to reverse if it's right. a left cartwheel will always be right foot forward and left foot back on the landing. this means on the end of the beam the same. whether it is cartwheel or round off. keep this in mind as i go along.
once the left round off rights itself to vertical, a couple of cause and effects take place. the left round off can be a right twist barani BECAUSE the hands don't touch a surface. when the right hand pushes from the floor, the legs cartwheel down, the legs close and the body becomes right side up is where you find counter torque because the left arm comes up from the floor first. remember, both arms/hands are placed on the floor to the left of the body. but when the body finishes near right side up vertical, the arms/hands are coming from the RIGHT side of the body. so, the left side of the body must 'borrow' weight from the right side of the body thru the left arm or the body may not come to a stand.
you'll see this often with beginners when they can't get up. they do a left cartwheel. their left arm/hand comes up from the floor first. but the right arm/hand stay on the floor. they then land in a sideways squat. this is due to the left leg NOT closing rapidly to the floor on the cartwheel and pushing off the floor from the right hand/arm simultaneously. hence, the use of those rubber hands and carpet squares. lol.
so then, when the body becomes upright the body becomes left sided with a load in the right leg. all left twisting is initiated from the right side of the body. if it's tumbling, it comes from the right foot, calve and quad. if it's vaulting, it comes from the right arm, shoulder, etc; a left twist handspring full is a good example and less complicated to visualize than, let's say. a Cuervo. when the body leaves the horse, the right arm drops. this is because the left side of the body needs to "borrow" the arms weight from the right side of the body in order to twist to the left. if you have seen any other method or technique you know how crappy they can look. the drop arm method is seamless and make sense in physics. understand?
if you ask the athlete to jump right twist at the completion of a left round off you will see that it is awkward. this is because the arms are already moving to the left side of the body. it is uncommon to see a left round off to a right twist arabian or back 1/2. the torque and load are forcing the body to twist left.
when you place a back handspring before the skill, this torque and load dissipates thru the body and floor during the back handspring. so now you could apply the rules of trampolining.
but twisting to the left from a left round off is not 'better'. it's not about what's better. it's about what works. so now apply this to beam dismount. as i said, if you left cartwheel round off your right leg will be forward and your left leg back. this is right side/right loading dominant that will create counter torque to the left side of the body allowing the athlete to seamlessly perform a left full, double full, triple full etc; the key is that the right foot is forward to punch. and most likely this athlete is right dominant. so then, the left foot stabilizes the punch, then the right foot/leg initiate twist to the left from the lower body, and then the right arm follows thru by wrapping to the left. it's seamless.
now go back and look at Nastia's early dismounts. she could never finish a triple full and without deduction. go look at what side cartwheel and what foot was forward when she punched the dismount. her inability to finish the triple was not a coincidence. so for those that switch their feet before the punch cause ostensibly they are doing the wrong side cartwheel/round off, they will be more successful performing 1 1/2, 2 1/2, etc; it is to inefficient and difficult to perform a double full to the left if the left foot is forward.
yet, i recently sent video of Carly Patterson to a coach in England to see what i'm talking about as there are EXCEPTIONS to these rules from time to time. Carly did a right round off. this means left foot forward and right foot back when her feet touch the beam upon completion of the round off. but everything Carly did on beam was right legged. aerial walkover, flip flop lay, etc; all done by kicking her right leg. but what did she do?
Carly switches her feet on the round off to have her RIGHT foot forward. why? because she is right dominant and needs her right foot forward just as her other tumbling on beam. and then she does a 2 foot snap down to punch with the right foot still forward. she needs her right foot forward to 'push' just as she does on all her other beam tumbling. the right leg is the strongest and the leg/brain that has memorized what it must do over countless repetitions. (this is what makes a switch pitcher/hitter so unique and rare. the majority could never do it.) Carly is an endomorph (lower center of gravity to the beam which is center of mass) and strong beyond comprehension. because what does she do next? with her right foot forward to punch, she performs an arabian double front to the right with right twist. remember above where i spoke of the crotch/thighs closing against the twist?
well you can see it here:
Carly Patterson - Balance Beam - 2004 Olympic All Around - YouTube
you will see the end in slow motion how the body was moving still to the left side of the beam. when she lands you can see she is off center to the left side of the beam. this is due to the right foot being forward which wanted to create a left twist to the left side of center axis. understand? and observe how the body is twisted during this tumbling series and not 1 body part is aligned over the center of the beam. and look at what the left leg must do to accommodate this phenomena as it leaves the beam. if Carly was not an endomorph and extremely strong she would not have been able to counter the forces of gravity that were pulling her in the opposite direction. and for those that know her history, she missed that dismount more than she made it. and thankfully, she made it when she needed to. she was a great athlete.
so then, when you have the left cartwheel and a right twist (trampoline) you will have a difficult time performing anything past a 1 1/2 twist. and yes, there have been a few that can 2ble full before puberty. the risk after is to the ACL. this is why coaches go to gainers or front twisting dismounts.
more later...i'll see if there are questions about this and then i'll move to vault. and remember again, gymnasts should twist the same direction going forward somi or backward somi.