GTO Preflop Ranges Explained

Poker preflop strategy used to be a stack of rules of thumb: open these hands under the gun, widen on the button, three-bet your big pairs. Solvers replaced the rules with math. A GTO preflop range is the output of that math: the exact hands, actions, and frequencies that make your preflop play unexploitable at a given stack depth, table size, and rake or ante structure.

This guide covers what a range really is, the five branches that make a preflop tree complete, what separates a good solve from a bad one, and how to actually use solved ranges to study.

What a "range" means

A range is a distribution, not a hand. When you open the cutoff, you are not opening one hand; you are opening a set of hands, each with a frequency. Some hands are pure raises. Some are pure folds. And a surprising number sit on the boundary and get raised only part of the time, which is why solved ranges show mixed frequencies instead of clean yes/no answers.

That last point trips up players coming from old-school charts. A rule of thumb says "open ATo from the cutoff." A solve might say "open ATo from the cutoff 100% of the time at 100bb, but only 60% at 40bb, and never under the gun." The hand did not change. The situation did, and the correct frequency moved with it. Learning ranges is really learning how those frequencies shift as the situation shifts.

The five branches of a complete tree

A range for one seat is only useful if it connects to the ranges around it. A complete preflop tree specifies an action for all 169 starting hands across every one of these branches:

• RFI (raise first in). Your opening range when the action folds to you. This is the foundation everything else is built on, and it widens predictably from early position to the button.
• 3-bet. Re-raising an opener, blending value hands with bluffs chosen for their blockers and playability. A 3-bet range that is all value is transparent and easy to play against.
• 4-bet and 5-bet. The escalation war. Facing a 3-bet, the solve constructs a 4-bet range of premiums plus specific bluffs, and defines when the stack goes in.
• Cold-call. Flatting an open without raising. This branch is condition-sensitive: rake and position decide whether a hand prefers to call, 3-bet, or fold.
• Defense. How the blinds respond to steals, including the wide, awkward blind-versus-blind battles that happen constantly and cost players the most.

Miss any of those branches and you do not have a strategy, you have a chart with holes in it. The reason to study complete solved trees is that these branches interlock: your correct 4-bet range depends on the opponent's 3-bet range, which depends on your open, and so on down the tree.

Why accuracy is the whole game

Two things separate a solve you can trust from one that quietly leaks.

Solve depth. A range solved to a low exploitability is one an opponent cannot profitably attack. A shallow solve can look completely reasonable at a glance and still bleed EV, because the frequencies are off in ways you cannot eyeball. "Looks right" and "is right" are not the same thing preflop, and the gap only shows up over a large sample when a balanced opponent quietly beats you.

Coverage. Real games are not all 100bb. Tournaments run from deep stacks down to 10bb shove/fold. Cash games swing from 40bb short to 200bb deep. Spin & Gos start around 25bb and collapse fast. A range set that only covers 100bb leaves you guessing in exactly the short-stack spots where mistakes are most expensive and most frequent.

How format changes everything

The same two cards can be a clear open in one game and a fold in another, because the conditions the range was solved for are different. This is the part generic charts ignore.

• Cash is about rake. Every pot that reaches a flop is taxed, so correct cash strategy tightens and shifts toward ending hands before the flop. The Simple GTO cash ranges are solved on the 500z rake structure, the standard for online 6-max, across 6-max, 4-max, 3-max, and heads-up from 200bb down to 40bb.
• Tournaments are about the ante. The modern 12.5% big-blind ante sweetens the pot, improves your pot odds, and widens correct opens compared to a no-ante game. The tournament ranges bake in that ante across 8-max and heads-up from 100bb down to 10bb.
• Spin & Go is about shallow, fast play. Three-handed hyper-turbos start around 25bb and the stack-to-pot ratio is tiny, so preflop decisions carry almost the entire win rate. The Spin & Go ranges cover the full 3-max tree from 25bb down to 8bb.

Take a chart solved for a rake-free 100bb game into a raked short-stacked table and it will have you playing too many hands, too passively, in the wrong spots. The conditions are not a footnote. They are the strategy.

How stack depth reshapes ranges

Within a single format, the tree changes as stacks change. Deep, you have room to open, get 3-bet, 4-bet, and still play postflop, so the full branch structure is live. As stacks get shorter, that structure compresses: 4-bet-or-fold replaces 4-bet-and-play, then raising gives way to open-shoving, until at the shallowest depths the game is almost purely all-in or fold. Learning the transitions, not just the endpoints, is what lets you play a 35bb stack correctly when your chart only memorized 100bb.

Common misconceptions about GTO preflop ranges

A few beliefs get in the way of using solved ranges well:

• "GTO is only for tough games." A solved baseline is what you deviate from in any game. Against weak opponents you deviate to exploit them, but you cannot measure a leak without knowing the correct line first. The baseline is more useful against soft pools, not less.
• "Memorize the chart and you are done." A single chart is one stack depth, one format, one set of assumptions. Real games move through depths and structures, so what you actually need is the pattern across them, not one frozen snapshot.
• "Ranges are just for opening." Opening is the easy part. Most of the money is in the branches that follow: 3-bets, 4-bets, cold-calls, and blind defense, where players improvise and leak.
• "Close-enough charts are close enough." At low stakes against passive players, small errors are cheap. As you move up and opponents start noticing imbalance, rounded-off frequencies become a readable pattern they can attack.

Clearing these up is half the value of studying a real solve: it changes what you look at and why.

How to actually study solved ranges

Do not try to memorize 169 cells one at a time. Study patterns:

1. Group by position and action. Learn the shape of an early-position open, then how it widens to the button, then how the blinds respond.
2. Bucket by stack depth. Ranges shift in recognizable steps as stacks get shorter. Learn the transitions, not just the endpoints.
3. Drill against the real files. Load the solved ranges into the free Simple Preflop solver and read the actual matrices with frequencies, rather than a static screenshot someone traced by hand.

New to any of the terminology here? The glossary defines the core concepts, and how to read a preflop chart walks through the 13x13 grid itself.

Why owning the files matters

Solved preflop ranges have an unusual property for a study tool: they do not go stale. A correctly solved 100bb 6-max opening range is right this year and right next year, because the underlying math does not change when your subscription lapses. That makes preflop ranges closer to a reference book than a service. You buy the book once and it keeps working.

When you own the files, you load them in the free solver whenever you want, online or off, with no login and no monthly charge. If a range is ever re-solved, you re-download the newer version from your account at no extra cost. The alternative, renting access month to month, means the day you stop paying you lose the exact ranges you spent months drilling. For a body of knowledge that does not expire, paying rent on it forever is the part that does not add up.

Which ranges do you need?

It depends on what you play:

• Cash grinder: the full cash tree across table sizes and stack depths, solved for the rake you actually pay.
• Tournament player: every stack depth from deep to shove/fold, with the ante in the tree, because a tournament stack is never one size for long.
• Spin & Go player: the hyper-turbo short-stack tree, where preflop is nearly the whole game.
• Serious about more than one: the complete library in a single purchase.

The Simple GTO bundles map to exactly those needs, delivered as files you download and keep. Buy once, own forever, no subscription. The ranges do not vanish the day you stop paying, and when a range is re-solved you re-download the update at no extra cost.

If you are just getting started, read how to read a preflop chart next, then load the files into the Simple Preflop solver and build a study routine around them.