6-max Cash 100bb RFI Ranges by Position

Raise-first-in, or RFI, is the foundation of your whole preflop game. It is the range you open when everyone before you has folded, and every other branch, the three-bets you face, the flats behind you, the blind defenses, is built on top of it. Get RFI right and the rest of the tree has something solid to stand on. Get it wrong and every later decision inherits the error. This guide walks through how a solved 6-max range widens from under the gun to the small blind at 100bb, and why.

The one-line rule, and why it holds

RFI ranges widen as position improves. Tightest under the gun, a little wider in the hijack, wider again in the cutoff, widest on the button, and then the blinds are their own story. That pattern is not a convention someone invented; it falls out of two facts that shift with every seat.

First, players left to act. From under the gun, five players can still wake up with a big hand and punish a loose open. On the button, only the two blinds remain, so a steal succeeds far more often. Second, postflop position. Late-position opens will usually be in position after the flop, where hands realize their equity better, so more of them are worth playing. Early-position opens are often out of position, so only hands that hold up under that disadvantage make the cut.

If the idea of a range as a distribution rather than a list is new, read GTO preflop ranges explained first.

Under the gun: tight still wins

From under the gun in 6-max, the solved range is disciplined. You are first to act with the whole table behind you, so you open a compact, high-quality set: the strong pairs, the strong suited broadways and aces, and a controlled amount of the next tier. The temptation is to add speculative suited hands "because they are suited," but many of them do not clear the bar this early, especially once rake is in the picture. A tight, confident under-the-gun range is one of the quiet marks of a strong cash player. It looks boring and it prints.

Hijack and cutoff: the range breathes

Moving to the hijack and then the cutoff, two players have already folded and fewer remain behind, so the range expands. More suited connectors, more suited gappers, more of the offsuit broadways and weaker aces come in. The cutoff in particular is a big step wider than the hijack, because you are one seat from the button and steals are landing more often. This is where a lot of your profitable, non-premium volume lives, so it is worth knowing the exact edges rather than eyeballing them.

The button: how wide is wide?

The button opens the widest range at the table, and correctly so. With only the blinds behind and guaranteed postflop position, a large chunk of the deck shows a profit as an open. But "widest" is not "any two cards." There is still a boundary, and both over-folding strong-enough buttons and over-opening trash are mistakes. The solve draws a precise line, and the hands right at that line are exactly the ones players get wrong by feel. The tax matters here too: even the button pays rake when it sees a flop, which trims the very bottom of the range compared to a rake-free chart.

Reading a couple of boundary hands

The value of a solved range is in the edges, so look at how a single hand moves across seats. Take a hand like KTo. Under the gun it is a fold in a disciplined 6-max range: too dominated, played out of position against a table full of players who can wake up with a better king or an ace. Move it to the cutoff and it becomes a comfortable open, because two players have folded and postflop position is more likely. On the button it is a clear open. The two cards never changed; the seat did, and with it the number of players behind and your postflop position. That is the whole logic of position-based RFI in one hand.

Now take a suited hand like 76s. This one behaves differently, because suitedness and connectedness give it playability that KTo lacks. It comes into the range earlier and more happily, because even when it is behind it can flop straights, flushes, and draws that realize equity and win big pots. Comparing a dominated offsuit broadway against a connected suited hand is the fastest way to feel why the solve treats "high card strength" and "playability" as different things.

What changes at other stack depths

The 100bb range is the reference point, but real cash games move around it, and the solve moves with them. Shorter, the opens compress: in the cash trees the standard open steps down toward 2.2bb around 60bb, because you are risking a larger share of your stack and want to keep the price down, and the ranges tighten slightly as the room to maneuver postflop shrinks. Deeper, toward 150bb and 200bb, playability matters even more, because implied odds grow when stacks are deep, so the hands that can win a huge pot gain a little value. The shape stays the same, tight early and wide late, but the exact widths and sizes shift with depth, which is why owning every depth beats memorizing one.

The blinds are a different game

The small blind is not a normal RFI seat. Facing only the big blind, it plays a distinct raise-or-complete strategy, mixing raises with limps to protect its weaker holdings, which is a separate topic from open-raising into a full table. The big blind, meanwhile, never RFIs; it only ever responds to someone else's open. So when you study "opening ranges," the four true RFI seats are under the gun, hijack, cutoff, and button, and the blinds get their own treatment. The Simple GTO cash ranges include full SB-complete and blind-versus-blind trees precisely because this spot is so different and so frequent.

The common leaks

• Opening too wide from early and middle position. The most expensive RFI leak. Those hands play raked, out-of-position pots against strong continuing ranges. Trim them.
• Under-opening the button. Leaving money on the table by folding buttons that are clear steals.
• One-size-fits-all width. Using your cutoff range on the button, or your button instincts in the hijack, blurs the position-by-position discipline that makes the whole system work.
• Ignoring rake. A rake-free chart overstates every range's width by a little. In a raked game, that little compounds. This is covered in depth in how rake changes preflop ranges.

How to drill RFI ranges

RFI is the highest-return thing to memorize cold, because it comes up every single orbit from every seat and it anchors the rest of the tree. A practical way to drill it: take one position at a time and learn its boundary, the weakest hands still opened, rather than trying to photograph all 169 cells. Everything clearly above the boundary is in, everything clearly below is out, and the boundary hands are the only ones you have to think about. Then move to the next seat and notice what got added. Under the gun to hijack to cutoff to button, each step adds a recognizable tier of hands, and learning the additions is faster than relearning the whole grid four times.

Once the four RFI seats are automatic, you have removed the most frequent decision in the game from your working memory, which frees you to think about the harder spots that actually vary hand to hand. Drilling the ranges in a solver you own, offline, is the fastest way to get there, because you can quiz yourself on the boundary hands repeatedly until they stop being decisions.

One more reason RFI discipline pays off: your opening range sets the terms for everything opponents do to you. A range that is too wide gets three-bet more, defended lighter, and punished postflop, because it is full of hands that cannot handle pressure. A tight, correct opening range gives your opponents fewer good ways to attack you, which quietly improves every later street. That is why RFI is not just the most frequent decision, it is the most foundational: the discipline you show on the first action of the hand echoes through the rest of it.

Own the exact ranges

You can carry the shape of this in your head, tight early, wide late, blinds are special. But the money is in the exact edges: which specific hands are in from the hijack, where the button actually stops, how the small blind splits raises and completes. Those edges are also exactly where opponents cannot copy you, because they require the real solve rather than a rule of thumb. The Simple GTO Cash Game Bundle has the complete solved 6-max RFI ranges at 100bb and every other stack depth from 200bb down to 40bb, plus the 4-max, 3-max, and heads-up trees, on the 500z rake structure, as files you own and drill offline.