Hand 1:

10/20pl 6m, $2000 eff
UTG raise $60, MP call, Hero call BB with Tc8c4h2h.
Fl(190) AhTh7h
Hero ch, UTG bets 95

If we defend 1-A of our range, the field is required to defend 67% vs this bet so UTG is indifferent to bluffing with his 0 equity holdings.

Hand 2

10/20pl 6m, $2000 eff
MP limp, BTN limp, Hero complete SB with KdKh9c8s, BB ch.
Fl(80) 7h7c3d
Hero ch, BB ch, MP bets 80

If we defend 1-A of our range, the field is required to defend 50% vs this bet so MP is indifferent to bluffing with his 0 equity holdings.

If we defend 1-A of our bluff catchers, we'll be folding a lot more than 1-A of our entire range.

For example, in Hand 2, approximately 15-20% each of BTN, SB, and BBs ranges could be classified as 'bluff catchers', (defining bluff catchers as their combos of naked QQ, KK, AA, and medium 7xxx). If each player is defending 1-A of this subset of combos, that's very different than defending 1-A of their entire range. This decision lies in making the bettor indifferent between betting or checking with his bluffs.

Questions:

1) Do we want to defend 1-A of our entire range or do we want to defend 1-A of our bluff catchers?

2) Is each player equally responsible for defending the flop, or are some players more responsible than others?