Part: Part Five - Betting Before the Flop

Calling a shove

Pre-flop
Blinds 100 / 200Pot 2,700 (13.5 BB)BBA♣J♠● 25,000 (125 BB)YOUto actBTN● 2,400 (12 BB)Short buttonall-in 2,400 (12 BB)SBfoldsD

A short-stacked button open-jams 12 BB. The small blind folds and you're in the big blind with A♣J♠.

A 12 BB button open-shoves; you hold A♣J♠ in the BB, closing the action. Best?

WhyClosing the action, you're laying only what the pot demands: better than 1.2-to-1 means A-J needs about 46% to break even. A twelve-blind button jam is stuffed with weaker aces, kings, and suited junk, and A-J clears that bar comfortably. The math makes the call - his exact holding doesn't.
What happensHe turns over K-9 and your A-J holds. Worth being honest about why: you were calling the range and the price, so this is a winning call whether or not the board cooperates.
Facing a wide short-stack shove, pot odds and equity decide it, not nerves. Getting a good price against a range you're ahead of, you call - and you'd make that same call every time, including the nights it doesn't hold.

You call an all-in on price and equity, never on fear - the wider his shoving range, the less hand you need to profitably look him up.