Beginners try to guess exact cards: "he definitely has Ace-King". A skilled player reasons differently: "he opened from UTG and bet the flop — what collection of hands would take this line?". The complete set of hands a player can hold in a given spot is called a range.
Pinpointing two exact cards is virtually impossible, but estimating a range is remarkably reliable. A decision that produces positive expected value (+EV) against an entire range remains profitable in the long run, even if your opponent occasionally shows up with an unexpected holding.
The 13x13 Matrix
All starting hands fit cleanly into a 13 by 13 grid containing 169 hand types:
- Diagonal — 13 pocket pairs, from AA down to 22.
- Above the diagonal — 78 suited hands, designated with an s: AKs, T9s.
- Below the diagonal — 78 offsuit hands, designated with an o: AKo, T9o.
Compare two ranges below: the Button opens wide, while the Big Blind defends even wider because they already posted 1 bb and receive discounted pot odds.
Hand Types vs Specific Combinations
A hand type and a specific card combination are very different. AKs is one hand type, but it comprises four distinct combinations: A♠K♠, A♥K♥, A♦K♦, and A♣K♣. You must count combinations (combos) because they appear with vastly different frequencies.
- Pocket Pair — 6 combinations: the number of ways to pick two suits out of four.
- Suited Hand — 4 combinations: one for each suit.
- Offsuit Hand — 12 combinations: 4 suits for the first card times 3 remaining suits for the second card.
Blockers (Card Removal)
Cards in your hand cannot be in your opponent's hand. This physical constraint changes their range, an effect known as blockers or card removal.
Hold A♠ — your opponent has only three aces remaining, cutting their AA combinations from 6 down to 3 combos. Hold A♠ K♦ — their ace and king combos are cut in half, and their AK combos drop from 16 down to 9. Verify this on the combination counter below.
Mixed Strategies
In GTO charts you will often see shaded cells indicating a hand is played only a percentage of the time. This is a mixed strategy. When two actions have virtually identical EV, optimal strategy randomizes between them (e.g. raising A5s 50% and folding 50%) to remain unpredictable. As a beginner, choosing the dominant action is completely fine: EV loss from simplification is minimal.