What Is Aggression Factor in Poker?

Aggression factor is a postflop statistic that divides a player's bets and raises by their calls. At 1.0 they call once for every aggressive action they take; at 4.0 they bet or raise four times for every call. It describes the shape of someone's postflop game, which makes it the fastest read available on how a hand against them will go.

How the number is built

Trackers compute it from postflop actions only, and folds never enter the sum.

Aggression factor = (bets + raises) divided by calls

That omission matters. A player who folds three flops out of four and bets the one they continue with posts a healthy number on almost no hands played, so treat anything under a few hundred postflop hands as noise. Most trackers also split the stat by street, and the turn and river figures separate real aggression from automatic flop c-betting.

Aggression factor	Typical player
Below 1.0	Calling station: bets the nuts, calls with everything else
1.5 to 2.5	Passive regular: honest bets, folds too much to pressure
2.5 to 3.5	Solid winning 6-max regular
Above 4.0	Barreller: heavy bluff frequency, collapses against raises

What it looks like in a hand

You open the BTN to 2.5bb with A♣J♣ and the BB calls. The flop comes Q♠7♦3♥, you continuation-bet $20 into $30, and they raise to $65.

Against the 0.8 player that raise is a set or two pair, and A-high is a fold requiring no thought. Against the 4.5 player the same raise contains 65s, 98s and every backdoor flush draw, so calling once and re-evaluating the turn is the profitable defence.

The cards are identical in both hands. Only the frequency behind the raise moved, and that frequency is what your decision is actually about.

How to play against it

Two adjustments cover almost every opponent you will meet.

• Low aggression factor: value bet thinner and stop bluffing. They call down with weak pairs and raise only with the nuts, so your bluffs have no fold equity and your strong hands get paid.
• High aggression factor: check-call more and let them keep firing. Your bluff-catchers rise in value, and check-raising the turn punishes a range built mostly of air.

Both adjustments swing your results harder than they change your edge, because you win fewer and bigger pots. A poker variance calculator will show you how long a genuine 5bb/100 winner can sit underwater before the sample settles.