Why stack depth changes everything about the ranges you open and defend
When you sit down at a table, one of the first things you should assess is stack depth. Stack depth—usually expressed in big blinds—determines how many streets you can realistically play and what kinds of hands have the implied odds to be profitable. You’ll find that a hand that’s a powerhouse at 150bb can be mediocre or even a leak at 20bb. Understanding this will help you construct ranges that fit the situation instead of forcing a one-size-fits-all approach.
Think in terms of options and commitments. Deeper stacks give you multi-street maneuverability and more room for big implied-value hands, while shallow stacks force more preflop and immediate postflop commitments. Recognizing that difference allows you to build ranges that exploit both your opponents and the structure of the game.
Core principles for building ranges at different stack depths
Use stack-to-pot ratio (SPR) and hand playability as your compass
SPR—the ratio of effective stack to pot—directly affects what hands you should include in your range. At high SPRs (deep stacks), you need hands that can realize equity across many runouts; at low SPRs (shallow stacks), hands that have immediate showdown value or high preflop equity become more attractive.
- Deep stacks (100bb+): Favor hands with postflop playability: suited connectors, small-to-medium pocket pairs, suited aces, and broadway combos that can make strong nut or near-nut hands. Your range should be more mixed and include speculative hands that can extract large implied odds on later streets.
- Medium stacks (40–100bb): Shift toward a balance between playability and raw equity. Hands like AQs, KQs, mid pairs, and some suited connectors remain valuable because they can still win sizable pots but are less dependent on huge implied odds.
- Shallow stacks (20–40bb and shorter): Prioritize high immediate equity and straightforward value: high pocket pairs, strong broadways, and suited aces. Speculative hands that need deep stacks to realize value should be removed or played less often.
Position, opponent type, and bet sizing interact with stack depth
You always need to fold stack depth into other variables: your position at the table, the tendencies of the opponent you face, and preflop/continuation bet sizing. For example, in late position with deep stacks you can open a much wider range because you’ll get more bluff-and-value opportunities postflop. Conversely, facing a large preflop shove with short stacks transforms many marginal hands into clear folds.
Bet sizing also modifies effective stack depth. A large open or a small blind size can change SPR immediately, so you should adjust ranges dynamically rather than mechanically. Consider how a 3x open from the button versus a 2.2x open affects the pot you must navigate postflop and adapt your calling and folding thresholds accordingly.
With these principles in place—SPR awareness, hand playability, and interaction with position and sizing—you can begin to sketch concrete opening and defending ranges for deep and shallow scenarios. In the next section you’ll see practical preflop range examples and step-by-step guidance for translating these principles into specific hands and actions at the table.
Concrete preflop ranges by stack depth and position
Here are practical opening and defending examples you can apply immediately. These are starting points — tweak them for table dynamics and opponent types — but they show how much your range should shift as stack depth changes.
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Deep stacks (100bb+), late position open (CO/BTN):
Open wide to exploit postflop maneuverability: roughly 35–45% on the button, 25–35% in the cutoff. Typical hands: all broadways (KQ, KJ+), AQo+, Axs, most suited connectors 54s+, suited one-gappers like 64s–98s, and small–medium pairs 22–99. Against opens, defend by calling wider — include many suited connectors and mid pairs — and 3-bet selectively with polarized ranges (QQ+, AK, A5s–A4s as bluffs).
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Medium stacks (40–100bb), cutoff/button opens:
Open tighter: approximately 20–30% from the button, 15–22% from cutoff. Keep most broadways, AQ, mid pairs (66–TT), and remove the weakest connectors (e.g., 54s becomes less attractive at the low end). Defend by calling with hands that can realize equity without relying on huge implied odds: suited Aces, KQs, KJs, 76s–98s, and pocket pairs down to 55 depending on pot odds and aggressor.
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Shallow stacks (20–40bb), late position open and shoves:
Open and defend with straightforward equity hands: button opens around 12–18% (AQ+, KQ, QJs, 99+), cutoff tighter. Remove speculative small connectors and low pairs. Versus a raise, prefer shove-or-fold thresholds— hands like AJs+, AQo, 88+ and occasionally KQo should be in your shove/call set when SPR is low.
Examples of specific defending adjustments: facing a 3x open from the CO with 120bb effective, call with 65s, 44, KTs, and KQo; with 30bb effective, fold 65s and call/shove only with 88+, AJs+, AQo+ depending on stack and opponent tendencies.
Translating preflop ranges into postflop plans and 3‑bet strategy
Preflop ranges are only useful if you have a clear plan for how to play those hands across streets. Use the following stepwise approach:
- Label your hand types. For each hand in your range decide if it’s: value (nuts/near-nuts), semi-bluff (combo draws, backdoor), or showdown (high card, small pair). This prevents overcomplicating lines postflop.
- Define line preferences by SPR. High SPR: favor small-ball lines—check-call, delayed aggression, multi-street bluffs. Medium SPR: mix continuation bets and turn barrels; prioritize hands that can comfortably barrel twice. Low SPR: plan for commit-or-fold lines—lead for value or check-fold versus resistance.
- 3‑bet strategy tuned to depth. Deep stacks: 3‑bet more for balance and postflop playability (suited broadway combos and polarized bluffs). Medium stacks: tighter 3‑bet value range (QQ+, AK, AQs) and fewer light 3‑bets. Shallow stacks: 3‑bet sizing should discourage callers or set up immediate shove; favor value-heavy 3‑bets and use shove sizing when optimal.
Finally, always re-evaluate based on opponent tendencies: aggressive callers who don’t fold to c-bets deserve tighter bluffs and more value in your opening range; passive players who fold often to pressure let you widen your bluff frequency even with shorter stacks. Practice these concrete range-and-plan templates and you’ll find your preflop decisions become faster and your postflop execution clearer across stack depths.
Turning ranges into results
Make the ideas here concrete: set a short, focused practice plan and measure progress. Example commitments that produce improvement quickly:
- Daily 20–30 minute range review: pick one stack depth and one position, build/open the range, then compare decisions against a solver or equity tool.
- Session checklist: note three hands where stack depth changed your plan, tag whether you folded, called, or 3‑bet, and review those with a coach or study partner.
- Adjustment log: track opponent types (sticky callers, high fold vs c-bets, aggressive openers) and the range changes you made — revisit after 5–10 sessions to validate which adjustments worked.
For tools to test and refine your ranges, try a solver or equity calculator that supports different effective stack sizes. A good starting point is GTO+ solver, which lets you simulate deep, medium, and shallow-stack scenarios and see how optimal ranges evolve.
Frequently Asked Questions
How much should I deviate from these ranges versus very passive opponents?
Against passive players who fold too much to aggression, widen your bluffing and steal frequencies, especially in medium and deep stacks where postflop pressure earns folds. Conversely, versus passive callers who call down light, tighten and bias toward value hands. The core adjustment is shifting share of bluffs versus value — keep your value/core hands stable and alter the marginal speculative hands.
When should I switch from calling to 3‑betting as stacks get deeper?
As stacks grow, emphasize 3‑betting more for fold equity and postflop playability — typically increase polarized 3‑bets with suited broadways and strong pairs when you expect multi-street play. At medium depths, prioritize value 3‑bets (QQ+, AK) and reduce light 3‑bets. The exact inflection point depends on opponent tendencies: if opponents call 3‑bets too often, tighten and favor postflop play with single raises.
Are there quick drills to internalize shove/call thresholds for shallow stacks?
Yes. Run short practice drills: select common stack sizes (20bb, 25bb, 30bb), generate open sizes and simulate common opponent opens; for each, list hands you would shove, call, or fold. Repeat with real-hands review after sessions and use an equity tool to confirm breakpoints (e.g., where AJs+ or 88+ become profitable to shove). Repetition plus feedback is the fastest route to reliable shove/call instincts.