So I started to do some digging in the good ole cranium and realized a cold 4b’ bluff can be a profitable play . Say MP opens for 3x, and a LAGdum OTB 3b’s to 12bb’s. We 4b’ in the sb and take down the pot. We’re up 15bb’s. We can’t really ask for more before a board is even dealt. The only problem is when the BU 3b’s to 12bb’s, we in turn are raising an additional 12-15bb’s. It’s a big risk/reward scenario. I recently read phil gordon’s ‘little gold book’. I’m glad I took good notes on the book. (I let a friend borrow it, lol, he mentioned to me that he thinks the author over-thinks NLHE.)
EX.
Note: most villains won’t playback to a cold 4b’ w/out QQ+,AK .
QQ+,AK = 34 combos
An agro villain in CO opens for 3x 45%(602 combos) 34/602 = 5.6% villain has QQ+,AK
BU (12% 3b’er from LP) 3b’s to 12x 12%(166 combos) 34/166 = 20% villain has QQ+,AK
So, when we cold 4b’ bluff from the blinds to 22x vs. these two villains 94% co folds, and 80% BU folds 94% X 80% = 75%
75% of the time we win 15bbs , and 25% they playback and we fold and lose 22bb’s
75% X 15 = +11bb’s when bluff works
25% X -22 = -5.5bbs when we fold
EV = +5.5bb’s

Doing these combinatorics vs. different hand ranges is great EV practice. BTW, my notes say even w/ a 50% opener. If our 3b’er 3b’s 9% or less. This is –EV..