Part: Part Ten - Adjusting to Different Stacks

You can't bluff a committed stack

Pre-flop
Blinds 400 / 800 (100 ante)Pot 2,100 (2.6 BB)Big blind is committed • no fold equityBTN7♠4♠● 50,000 (62.5 BB)YOUto actSBfoldsBB● 1,600 (2 BB)2 BB shortwill callD

Folded to you on the button with 7♠4♠. The big blind is a 2 BB short stack who is pot-committed and will call almost anything.

Button with 7♠4♠; the BB is a 2 BB stack who'll call any two. Best?

WhyThe 2-BB big blind calls a raise or a shove with literally any two cards, so there's nothing to bluff - every chip you commit with 7-4 suited heads to a showdown you'll often lose. Strip away fold equity and aggression stops being pressure; it's just a coin flip you volunteered for. Save the chips for a hand that actually beats his random range.
What happensYou fold the 7-4 and wait for something worth showing down. No fold equity means no steal - raising here just donates.
You stopped trying to steal from a stack that can't be moved: with a 2-BB opponent calling any two, there was no fold equity, so you kept 7-4 in the muck and waited for a hand that beats his calling range.

Fold equity is the entire point of a steal. Against a pot-committed short stack who calls with any two, that equity is zero - so only invest chips in hands you'd happily table.