So about 8 mins into this video :

http://www.runitonce.com/pro-training/videos/range-protection-2/

and Galfond in this one:

http://www.runitonce.com/pro-training/videos/2-table-51-6-max-zoom-nlhe-live-sess/

They are 3/4bet bluffing hands which won't get better to fold or worse to call. I'm sure I'm wrong here, but I just don't see why that is a good move. I mean surely if the villain has hands that will fold in their range, then we want to be keeping them in because we likely dominate them. The only reason I can see is you have 1 blocker to them hitting a pair on the flop, but this is only 1 out of 6 so hardly a big decrease. Anyway hoping someone can explain this to me, thanks in advance.