Why think in ranges
You can almost never know exactly what your opponent holds. What you can ask is which hands they would play this way. A player who raises from under the gun does not have a random hand, and does not have exactly aces either; they have one of a few dozen different hands. That list is their range, and every later action removes hands from it.
169 hands, 1,326 combinations
There are 1,326 ways to be dealt two cards. Many are the same hand for poker purposes: A♠K♠ and A♥K♥ play identically. Group them and you get 169 starting hands:
- 13 pairs (like 77), each made 6 ways.
- 78 suited hands (like AKs), each made 4 ways.
- 78 offsuit hands (like AKo), each made 12 ways.
Check: 13 × 6 + 78 × 4 + 78 × 12 = 1,326. Notice that offsuit hands are three times as common as suited ones, which is why a hand like AKs feels rare. Each way of making a hand is a combo, and counting combos is how you compare ranges.
The notation
- AKs means ace-king suited. AKo means ace-king offsuit. A pair has no letter, like QQ.
- A plus means "and everything better". 77+ is 77 through AA. A2s+ is A2s through AKs. ATo+ is ATo, AJo, AQo and AKo.
- A dash is a stretch between two hands. K5s-K9s is K5s, K6s, K7s, K8s and K9s.
- Ranks are written A, K, Q, J, T for ten, then 9 down to 2.
A real example
The Blindspot Poker opening range for under the gun (the first seat to act at a 6-handed table) is written as:
77+, A2s+, K5s+, Q9s+, JTs, ATo+, KJo+
Read it left to right. Pairs from sevens up (8 pairs, 48 combos). Every suited ace (12 hands). Suited kings down to K5 (8 hands). Suited queens down to Q9, plus JTs. Then only the big offsuit hands: ace-ten or better, and king-jack or better. Add the combos up: 48 pairs, 96 suited and 72 offsuit make 216, or 16.3% of all starting hands. From the button the same chart opens about 40%, which you can see by switching seats on the starting hand chart.
Reading a 13 × 13 chart
Range charts put the 169 hands on a grid. Pairs run down the diagonal, suited hands sit above it and offsuit hands below. Highlighted squares are hands in the range. Strong hands cluster in the top-left corner, so a tight range looks like a block there, and a wide range spreads along the edges to include suited aces and connected cards.
Narrowing an opponent's range
Start with what they did before the flop. An early-seat raise means a range like the one above. A call is usually weaker than a raise, since the strongest hands tend to raise. Then each street cuts it down. If the board is K-7-2 and they bet again, hands with a king or a pair stay in, and hands like QJ that missed the board are more likely to be bluffs or to fold. You do not need to be exact. You need to ask, each time: "which hands would do this?"
Blockers change the counts
The cards in your own hand are not available to your opponent. If you hold an ace, only 3 aces remain, so they can have pocket aces 3 ways instead of 6, and ace-king 12 ways instead of 16. This is why holding the ace of a suit makes a flush less likely for them, and why a hand that blocks the strongest hands in their range makes a better bluff.
Test your own ranges with the starting hand quiz, learn which seat opens what in poker position explained, and see how range thinking helps bluffing in when to bluff.