How to Read a Preflop Poker Chart: The 13×13 Grid

A preflop poker chart is a 13×13 grid with 169 cells, one for every distinct starting hand in Hold’em. The 169 cells stand for all 1,326 possible two-card combinations. Pairs run along the diagonal, suited hands sit on one side of it and offsuit hands on the other, and the shading of each cell shows what the chart assigns to that hand.

Reading one takes three steps: find the cell for a hand, read what its shading or label says, and check what the chart assumes. The first step is simple geometry. The third is the one most readers skip, and it decides whether the chart applies at all, because every chart is built for a particular position, stack depth and game format.

This guide covers the layout of the grid, how many combinations each cell represents, a worked example that turns shaded cells into a percentage of hands, how to read shading and labels, the most common mistakes, and why charts for the same spot can differ. It explains how charts work and does not tell anyone what to play.

What a Preflop Chart Is and What It Assumes

A preflop chart is a reference table that records, for each starting hand, what a particular source assigns to it in a particular situation. It is built from assumptions: where the player sits relative to the dealer button, how many big blinds each player has, which game format is being played, and what the opponents are expected to do.

Those assumptions are part of the chart, even when they are printed only in the title. A chart without its assumptions is incomplete. “Button, 100 big blinds, cash game” describes a different situation from “10 big blinds, tournament, facing a raise”, and the shaded cells will differ between them.

A chart is a summary, not a proof. It compresses a large amount of analysis into a grid that can be read in seconds, and the price of that compression is that exceptions, adjustments and uncertainty are not visible in it. Treat it as a starting reference whose limits are known.

The 13×13 Grid: Pairs, Suited and Offsuit Cells

The grid has 13 rows and 13 columns, one for each rank from ace down to 2. The cell where a row and a column meet is a starting hand type. The same rank on both axes is a pair, so all 13 pairs fall on the diagonal from the top left to the bottom right. Every other cell is an unpaired hand.

In most charts, suited hands are above the diagonal and offsuit hands below it, so the cell in row A and column K is AKs (ace-king suited) and the cell in row K and column A is AKo (ace-king offsuit). Some charts flip the sides, so a chart’s legend or the first few cells should be checked before reading it.

The cells are not equal in size, because each one stands for a different number of combinations. A pair such as A♠ A♥ can be dealt in 6 ways, an unpaired suited hand like A♠ K♠ in 4 ways (one per suit), and an unpaired offsuit hand like A♠ K♥ in 12 ways (4 × 3 suit pairings). The pair count is the basis of the 1 in 221 figure for pocket aces: 6 ÷ 1,326.

One cell is worth 0.45% of all starting hands if it is a pair (6 ÷ 1,326), 0.30% if it is suited (4 ÷ 1,326) and 0.90% if it is offsuit (12 ÷ 1,326). The offsuit half of the grid holds about 70.6% of all hands, even though it is the same number of cells as the suited half.

Worked Example: From Shaded Cells to a Percentage

Chart percentages come from combinations. Suppose a chart shades these cells (a purely illustrative selection, not a recommendation): the pairs 77 through AA, the suited hands AJs, AQs and AKs, and the offsuit hands AQo and AKo. That is 8 + 3 + 2 = 13 shaded cells.

The shaded set covers 48 + 12 + 24 = 84 combinations, and 84 ÷ 1,326 = 6.3% of all starting hands. Counting cells instead gives 13 ÷ 169 = 7.7%, which overstates the share because the average cell is worth 1,326 ÷ 169 = 7.8 combinations, while these shaded cells average 84 ÷ 13 = 6.5. The right figure is always the combination count.

The same method works in reverse. If a chart labels a range as “top 10% of hands”, that means about 133 of the 1,326 combinations (10% × 1,326 = 132.6), and the number of cells it covers depends on how many pairs, suited and offsuit hands are inside it.

Reading Shading, Labels and Assumptions

Shading is the chart’s language, and the legend defines it. A typical chart uses a color for each action available in that situation, and a blank or neutral cell for hands that are not assigned any of them. A different legend means a different meaning, so the colors cannot be assumed from one chart to the next.

Many charts also show mixed cells, split or partly shaded. A cell shaded 60% in one color and 40% in another is usually read as a frequency: the chart assigns the first action to a share of the combinations or occasions and the second to the rest. How the split is drawn varies, so the legend or the chart’s notes should be checked.

The title or caption carries the assumptions. Look for the position, the stack depth in big blinds, the game format (cash or tournament), the number of players, and the situation the chart covers, such as the first player to act or a player facing a raise. If any of these is missing, the chart cannot be placed in a real situation.

Equity numbers sometimes appear in the cells. Those values come from the same enumeration an equity calculator performs, against some assumed range, and they change if the assumed range changes. See outs and equity for what a figure like that does and does not measure.

Common Mistakes When Reading a Preflop Chart

The first mistake is counting cells instead of combinations. A chart with 20% of its cells shaded does not cover 20% of hands, because cells are worth 4, 6 or 12 combinations. Pairs are a small part of the grid: 13 cells but only 5.9% of hands.

The second is mixing up which triangle is suited. Reading AKo as AKs, or the reverse, changes the hand’s combinations from 12 to 4 and changes what the chart says about it. A third is using a chart outside its assumptions: a chart built for 100 big blinds says nothing reliable about 15 big blinds.

A fourth is treating a blank cell as a rule that the hand is never used. A blank may mean that the hand is not assigned an action in that situation, or only that the chart does not cover it. A fifth is treating a chart as universal. It is one source’s output under one set of assumptions, and an unshaded or shaded cell is not a guarantee about results in any single hand.

Why Charts Differ, and Other Chart Formats

Two charts for the same position and stack depth can still disagree. The assumptions behind them differ: the opponents they model, the rake they assume, the bet sizes they allow, how finely they split actions, and whether the author rounded mixed actions into single colors for readability. Small differences at the edges of a range are common, and they do not mean that one source made an arithmetic error.

Charts also come in more than one format. Besides the 13×13 starting-hand grid, there are push-or-fold charts for short stacks, which usually index the hand against the stack size in big blinds, and odds tables, which list probabilities or required equity. All of them are summaries of calculations, and the safe habit is the same: find the assumptions, find the legend, then read the cell.

Poker involves real financial risk, and no chart removes it. A chart describes a reference choice for a situation, not an expected result for the next hand, and short-term results are driven largely by luck.

Where Chart Numbers Come From

Charts are summaries of numbers that can be rebuilt. The count of combinations in each cell connects directly to the starting-hand probabilities, and the equity values that sometimes appear in cells come from enumeration. Reading a chart well means knowing where its numbers come from, which makes it easier to see what it assumes and where it stops.

The same habit applies to odds tables. A pot-odds table is the formula in how to calculate pot odds evaluated for common bet sizes, and an outs table is the outs arithmetic evaluated for common draws. Rebuilding a few entries by hand is the best way to trust, and to check, any table.