Part: Part Twelve - Heads-Up

Defend the big blind wide

Pre-flop
Heads-up • Blinds 400 / 800Pot 2,800 (3.5 BB)BBJ♦4♦● 20,000 (25 BB)YOUto actBTN● 20,000 (25 BB)Opponentraises 2,000 (2.5 BB)D

Heads-up. The button raises to 2,000 and you're in the big blind with J♦4♦.

Heads-up, button raises to 2,000; you hold J♦4♦ in the BB. Best?

WhyDo the math on the price first: better than 2-to-1 means you only need about a third equity to continue, and against the range a button opens heads-up, J-4 suited clears that bar. The suit adds flush potential and backdoor outs to play for, but the pot odds alone justify the call. Fold too much here and you simply gift a wide opener your big blind.
What happensYou call and take a flop with a live, suited hand that can make him pay when it connects. Defend too tight heads-up and the button prints against you.
J-4 suited is an easy defend - the button opens an enormous range and the price is better than 2-to-1, so most playable hands show a profit, and being suited gives it something to fight back with post-flop. Over-folding is the cardinal heads-up sin; a big blind that folds too much hands a wide opener free money.

Price plus a wide opener is the whole case for defending: getting better than 2-to-1, you only need to win about a third of the time, and a wide button range makes that easy.