all the techniques allow an ability to attack a flank..example is right tan , left jum , left bong/vu-strike , all feed the ability to attack the guys right side...in any sequence...change sides and the right tan is the now the right jum....
tan is a training position for a double action strike, as is jum sao ...
tan uses the outside leading edge with elbows low and in to ensure the correct deflection angles along the arm as it leaves this position to STRIKE and recovers back to elbows in to repeat endlessly.... If done correctly no 'force' can stop it except an equal counter line or a grab [ergo bil gee release moves].
Jum [side-palm makes the elbow turn inwards] uses the inside of the forearm , by keeping the elbows in and low , so the strike deflects force inwards , relative to our elbow/flank position....
All the techniques work to fight a flanked weakened side...
bongs move force left or right to clear for either arm capable of being a tan or jum in a nano second of response naturally to the line of force presented...thats why all the chi-sao for one...
each arm is tan/jum depending on the side you fight , and never leaves the centerline , because they are striking deflections. The brain signals the appropriate corrections to make the jum [inside] strike, reface and become a tan[ outside] strike.
It looks like a chain punch when used , not tan , jum, tan , jum etc... the elbow control trained from SLT up, is this thinking . To deliver a simple strike with either arm, so it works like 2...
example is instead of using a right hand pak sao to trap an arm and then strike over with a left strike lifting the elbow up and over to reach...
We use either arms forearms to align to the target , not the attackers arm...keeping the alignment we develop an invisible line of engagement IF its X'ed by another line of force....if the arm meets the other in a rotation strike attack, either arm will be able to act as the controlling AND striking arm in one beat. UNTHINKING without arm chasing lead actions , taking your ability to overwhelm , back to being equal arm for arm responses or worse 2 for one ...constantly , from trap to over trapping etc....
IF that is interrupted and the lead arm is stopped it becomes a jut, etc..to feed the rear hand ...chi-sao instills the appropriate response , unthinking .
The common idea being arm alignment drills to develop the twofold strike/deflect actions in both the tan strike and jum strikes...
on the dummy we train both extended to simply ensure the ability to strike with either and have correct alignment , not application I block your arm with one arm and then do a low rib strike with my other , over ...next move
schools that do this thinking usually fall aprt when sparring and do a pak sao kick boxing , bong in air elbows up trying to do reaching 'tags' to say "I got you".... reality is the 'tag' wouldn't drop or stop a fly ...a lot rely on the lop-chop [ chop having the elbow WAY up ] , because they dont know how to control or attack without grabbing themselves...grabbing is frowned on as the main response , when a jut allows attacking on the line ...
the tan , low gaun , tan, huen sao , jum sao ...are strike, deflect, strike , deflect , strike.
practice lateral attacking to, facing [chu-ying] with both strikes , again not to turn an 'attack the dummy' but imaging keeping going beyond the dummy using either strike
in rotation coupled with the attack line clearing, using man sao actions for the rear attack hand vu-sao
vu-sao is your best friend always free to attack..it is part of the thinking to not tie your own arms up and be unable to have a free vu-sao... no free vu-sao , bad .... another thing we do in chi-sao is pressure test to make a mistake of this ....not to fight each other like your opponent is going to do vusao ...