How GrindSense works

In Texas Hold'em each player gets two cards of their own, and five shared cards are dealt face up in the middle. You make the best five-card hand you can from any of those seven. You win the chips in the middle, the pot, by having the best hand at the end, or by betting so that everyone else gives up first.

The order of a hand

1. Blinds — Before any cards, the two players to the left of the dealer button post forced bets: the small blind and the big blind, usually twice as much. They make sure there is something to play for.
2. Preflop — Everyone is dealt two cards face down, their hole cards. The first round of betting starts with the player to the left of the big blind.
3. Flop — Three shared cards are dealt face up in the middle: the board. A second round of betting starts with the first player still in to the left of the button.
4. Turn — A fourth board card, then a third round of betting.
5. River — The fifth and last board card, then the final round of betting.
6. Showdown — If more than one player is left, the hands are shown and the best five-card hand wins the pot. Equal hands split it. If everyone else folds earlier, the last player left wins without showing.

A round of betting ends once everyone still in has had a turn and has put in the same amount, or all their chips. Then the button moves one seat to the left and the next hand begins.

What you can do on your turn

• Check — Pass without putting chips in. Only allowed when nobody has bet in this round.
• Bet — Put chips in when nobody has yet in this round.
• Call — Put in enough to match the biggest bet in this round.
• Raise — Put in more than the biggest bet. Everyone else then has to call the new amount, raise again, or fold.
• Fold — Give up your cards and any claim to the pot. Chips you already put in stay in it.
• All in — Put in every chip you have. You can then only win, from each other player, as much as you put in yourself.

At the table only the moves allowed right now are shown, so you cannot make an illegal one.

What beats what

From best to worst. Suits are never ranked against each other.

1. 1.A♠K♠Q♠J♠10♠Royal flush — Ace, king, queen, jack and ten of one suit.
2. 2.9♥8♥7♥6♥5♥Straight flush — Five cards in a row, all of one suit.
3. 3.Q♣Q♦Q♥Q♠7♦Four of a kind — Four cards of the same rank.
4. 4.K♠K♥K♦4♣4♠Full house — Three of a kind plus a pair.
5. 5.A♦J♦8♦6♦2♦Flush — Any five cards of one suit.
6. 6.10♣9♦8♠7♥6♣Straight — Five cards in a row, any suits. The ace can also be low: A-2-3-4-5.
7. 7.7♣7♦7♠K♥2♣Three of a kind — Three cards of the same rank.
8. 8.J♥J♣5♦5♠A♣Two pair — Two different pairs.
9. 9.10♥10♠K♦8♣3♥One pair — Two cards of the same rank.
10. 10.A♣Q♦9♠6♥3♣High card — None of the above: the highest card plays.

When two players have the same kind of hand, the higher cards win: a pair of kings beats a pair of sevens. If those are equal too, the next highest card decides, the kicker. Only five cards ever count.

The seats

Where you sit relative to the button is your position. Going clockwise from the button at a six-player table:

• SB — Small blind, just left of the button. Posts the small blind and acts first after the flop.
• BB — Big blind. Posts the big blind and acts last before the flop.
• UTG — Under the gun. First to act before the flop.
• MP — Middle position.
• CO — Cutoff, the seat before the button.
• BTN — The button (dealer). Acts last on the flop, turn and river.

Acting later is an advantage: you have seen what everyone before you did. That is why players in late seats can play more hands. Any other word you meet is in the Glossary.

Create a free account — by invitation while GrindSense is in its private test — then pick how you want to play:

• Practice — a single-player table you fully control: number of opponents, their styles, blinds, and stacks.
• Arena (live lobby) — 24/7 tables already running with AI players. Watch any table, or take an open seat and jump in.
• Tournaments — single-table Sit & Gos and multi-table events, freezeout or progressive knockout, with a rising blind structure, automatic table balancing as players bust, and virtual chip awards by finishing place. Every tournament award is play chips: non-transferable, with no cash, redemption, purchase or real-world value.

Nine archetypes, and they are not hand-tuned guesses. Each one's VPIP (how often it voluntarily puts money in before the flop) and aggression are calibrated against 2,351 real players from a large hand-history database, so each sits at an estimated percentile of that sample of real 6-max play rather than at a number someone thought felt about right. The figures below are for a six-handed table; at a full nine-seat table every archetype plays about a quarter fewer hands, so the order holds and the numbers shrink.

Tap any opponent at the table to see how to play against them.

Which of them actually learned to play? Two. The Q-Learner plays from a table of values it learned by playing the other bots at cash tables, and it is the seat you are facing when the badge says Q. The Neural Net is a policy network — first copied from the house engine, then trained the same way. Both keep to the range their width promises: a hand outside it is checked or folded, and the explanation says so. Inside it, how to play the hand — call, raise, how much, and everything after the flop — is the model's own. Every other archetype is an expert-authored engine: explicit ranges and betting rules, tuned against a database of real hands. The Adaptive seat is one of those too — it reads your statistics and attacks your largest deviation, which is a strategy we wrote, not a model that trained.

Each learned seat is dealt only while it passes two tests: it has to win enough against the other bots, and it has to play the style its name claims. One that fails either, or that cannot be loaded, is not seated. A Tight-Aggressive bot takes that chair, and it tells you so — the RL badge disappears, the seat introduces itself as TAG, and the bot styles board marks the style as benched. A badge never implies a neural net you are not playing against, and neither does a name.

When it's your turn, your options (fold / check / call / bet / raise) appear — only the legal ones. A few things that speed you up:

• Bet presets — ⅓, ½, ⅔, and full-pot buttons size your raise instantly.
• Pot odds on the call button — it shows the equity you need to make a call profitable.
• Keyboard — F fold, C check/call, R prime a raise, A prime all-in, then Enter to confirm.
• A countdown ring appears on the acting player at live tables.

In Practice, every AI decision comes with a plain-language explanation of why — the hand strength, pot odds, position, and read it's acting on. Crucially, the reasoning is honest: when a bot is bluffing, it says so. Read these to understand how strong players think through a spot. At Arena tables the bots keep their reasoning to themselves, as opponents do, with one exception: an Adaptive seat that has a read on you tells you which of your leaks it is attacking, in a direct message only you can see (the DM tab beside the chat). The rest of the coaching there comes from your own hands, in the review and the leak reports.

Coaching is woven through the app, not buried in a menu:

• HUD stats — VPIP, PFR, 3-bet%, aggression, and more, tracked across sessions.
• Leak detection — flags patterns like playing too many hands or over-folding the river, with how to fix each.
• Post-hand tip — a one-line lesson after hands where you slipped.
• Session recap — hands played, net chips, biggest pot, and your top leak when you finish.
• Analytics — how your stats move over time, by position and by street.
• Homework — the app picks what to work on next, based on what it has actually seen you do.

An opening range is the set of hands you raise with when nobody has entered the pot yet. It depends on your seat, because the earlier you act the more players are still to speak behind you, and the more of the hand you will play out of position. So the range starts tight under the gun and widens seat by seat towards the button.

This is the chart GrindSense teaches and grades against, as a share of all 1,326 two-card combinations (a pair is 6 of them, a suited hand 4, an offsuit hand 12):

• UTG — 17% of hands. Pairs, big aces, the best suited broadways.
• MP — 21%. The same, plus more suited connectors and medium pairs.
• CO — 28%. Suited aces and kings, offsuit broadways, small pairs.
• BTN — 45%. Nearly half of all hands: you act last on every street.
• SB — 35%, raise or fold when it folds to you. Limping invites the big blind in for a discount and hands them position.
• BB — no opening range. You already have chips in; your decision is whether to defend against the raise, which is a different chart.

Read the 13×13 grid on the Ranges page like this: pairs run down the diagonal, suited hands sit above it, offsuit hands below. The preflop drill under Drills marks you against exactly this chart, so what you study and what you are graded on are one thing.

Focused reps on one decision at a time, graded against a reference answer:

• Preflop ranges — should this hand be opened from this seat?
• Pot odds — is this call priced right for the equity you have?
• Short-stack shove/fold — the push-or-muck decisions that decide tournaments.
• ICM bubble — where chips stop being worth their face value.
• Equity quiz — how often does this hand actually win?
• C-bet spots — continuation betting on boards that do and don't suit you.
• 3-bet pots — playing the bloated pot you just created.
• River decisions — the street with no cards left to save you.

The Ranges page shows the same 13×13 opening chart the preflop drill grades you against, so the reference you study and the answer key you are marked against are never two different things.

• Replay — step back through any hand you've played, card by card and action by action.
• What if? — take the decision that cost you chips, change it, and watch the same hand play out from that fork with everything else identical.
• Share a hand — send a replay link to a friend.

• Rival ladder — a gauntlet of house bots climbed one archetype at a time, weakest first. You clear a rung by winning chips across your recent hands: a bar in big blinds per 100 hands that rises up the ladder, held over 500 hands, so a few lucky pots are not enough.
• Ranks — eighteen titles from Fish to GOAT, earned on results over time; the first twelve unlock higher stakes, bigger private tables and larger tournaments.
• Achievements & daily missions — targets that reward playing well rather than simply playing a lot; three fresh missions each day.
• Bankroll — tracks your roll and recommends the stakes it actually supports.
• Leaderboard & friends — ranks players, bots included.

• Sit in — take an open seat at a running table; your buy-in comes from your play-chip balance.
• Rebuy — bust out? Rebuy for the buy-in and keep playing.
• Sit out / I'm back — skip hands without losing your seat.
• Waitlist — table full? Join the queue; the buy-in is only deducted from your play chips when a seat actually opens, and you'll get a "take my seat" prompt.
• Watch — spectate any table (and chat) without sitting down.

Every hand commits a 256-bit seed before a single card exists, and the deck is shuffled from that seed with SHAKE256 — the extendable-output function from the SHA-3 family — using Fisher-Yates and rejection sampling. The shuffle is designed to avoid systematic bias toward any card or seat, and it is subjected to the statistical testing described below.

The shuffle is checked with the batteries used to test random number generators generally: dieharder's Diehard suite, NIST SP 800-22, and TestU01. Not only the underlying random source, but the dealt permutations themselves — a shuffle can be broken while its random source is perfect, so the cards are tested as cards.

This is not a gambling certification and does not claim to be. GrindSense is play-money and no regulator is involved. The testing exists so the question has an answer.

Your profile tracks lifetime stats and chip balance. Forgot your password? Use the reset link on the sign-in page. New to a term? The in-app Glossary defines it. You can delete your account from your profile at any time — see the privacy policy for what that removes and when.