After looking at the photos I disagree more with the first set of photos than the second. First, I would have to agree with hunt1 that the tan sau should be used as an attacking hand against the attacking limb. It's also in my opinion that if you are going to tan on the inside, it would be wise to expect the second free arm to attack you. Therefore I would'nt waste any further energy on the first arm, but would concentrate instead on covering the open area that the free arm still poses a threat. And whether or not the opponent chooses to strike or not - I would still cover the area that is open to attack and strike with whatever I thought suitable.
IMO - striking to the root/center to weaken a strike against you does'nt always work. Sometimes you can still end up on the losing side of an exchange.
Just different schools of thought, I guess.
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