How Often Do You Get Gin in Gin Rummy? Odds and Turns Measured

You'll almost never be dealt gin. The chance of being dealt gin is exactly 136,694 in 15,820,024,220, or about 1 in 115,733 hands. In play, how often you get gin depends on when you knock. Between the computer players in Poozee's Gin Rummy, players who knock as soon as they can get gin in about 2% of hands, while players who hold out for it, like our Hard computer, get it in 48%. If neither player ever knocks, someone goes gin in 89% of hands, and the typical gin came on the winner's 11th turn.

The dealt-gin odds are exact: the computer listed every gin hand there is. Everything else comes from seeded hands between the game's computer players, under the rules Poozee plays (our guide to how to play gin rummy has them in full): knock with 10 or less, aces low, and a draw when only two cards are left in the stock.

The odds of being dealt gin

A gin hand is 10 cards that all fit into melds: sets of 3 or 4 cards of a rank, and runs of 3 or more in a row in one suit. Every meld has at least 3 cards, so a gin is three melds (3 + 3 + 4 cards), two melds (3 + 7, 4 + 6 or 5 + 5) or one 10-card run. We had the computer list every combination of melds that don't share a card and count each hand once, however many ways it melds. 136,694 of the 15,820,024,220 possible 10-card hands are gin.

On Poozee you always knock by discarding after a draw, so the 11-card column is the one that counts on your first turn: with 11 cards to choose 10 from, your first draw gives you a gin about 1 in 11,229 times. That's about 10 times as likely as a dealt gin, and still rare.

To check the count, we turned to the game's own shuffle. In 1,000,000 deals on Poozee (2,000,000 hands), 15 hands were dealt gin, against 17.3 expected, and 180 held a gin once the upcard was added, against 178.1 expected. Both are within normal luck of the exact odds.

How often a hand ends in gin

For each of five players, we played 10,000 hands between two of the same player, on the same deals. Easy, Medium and Hard are the game's levels; the other two rows are Hard with a different rule for when to knock.

Medium and Easy knock as soon as they can, and only 2.4% and 2.9% of their hands ended in gin: somebody almost always gets down to 10 deadwood long before anyone gets to zero. Waiting for 5 or less raised it to 9.8%. Hard knocks at the first chance only while 23 or more of the stock's 31 cards are left, then holds out for gin, and nearly half its hands ended in gin. A draw means the stock ran down to two cards with nobody knocking.

Whether waiting is worth it is a different question from how often it works. Our gin rummy strategy guide tested knocking against holding out, stage by stage.

How many turns it takes to get gin

When both players play for gin, it takes a while. Here's how often someone had gone gin within their first few turns, in the 10,000 hands between two players who never knock. A turn is one draw, from the stock or the discard pile.

The typical gin came on the winner's 11th turn, and half of all gins came between the winner's 8th and 13th turns. The fastest took 1 turn (2 hands in 10,000) and the longest took 19. In 10.8% of hands, nobody got gin before the stock ran out.

In the hands between two Hard players, which end in gin about half the time, Hard's gins came on its 12th turn in the typical case. It knocks whenever it can early in the hand, so few of its gins come early.

Does a good deal help?

A little. We sorted each player's 20,000 dealt hands from the same never-knocking games by how many melds they were dealt:

Deadwood as dealt mattered even less: hands dealt with 40 or less deadwood went gin 47.3% of the time, and hands with more than 70 went gin 42.5%. Gin takes many draws, so the cards you pick up matter more than the ones you start with.

Count your outs, not your deadwood

Once you're close, the best guide to your chances is your outs: the cards you haven't seen that would give you gin on your next draw. Deadwood alone can mislead you:

With one loose card, any card that fits one of your melds gives you gin, because you throw the loose card away. In the first hand that's the 2 or 6 of clubs, the last 8, or the 10 of diamonds. With two loose cards, you need one card that melds with both of them: in the second hand, a third 2, so only the 2 of hearts or the 2 of clubs. Any of those outs you see in the discard pile is gone.

In 10,000 hands between two Hard players, every time a player could knock (47,704 times), we played the hand on with that player holding out for gin and the other playing Hard as usual. Outs were counted after the player's discard, among the cards they hadn't seen. Here's how often the player went on to get gin:

More outs meant more gins at every stage. Deadwood was a weaker guide: in the middle of the hand, 61% of players with 1 deadwood went on to gin, against 40% with 4 to 10. Late in the hand you also run out of time: with no outs late in the hand, the stock ran out first 50% of the time.

Pro tip: Poozee shows your deadwood under your cards and how many cards are left in the stock, so you always know your stage. Count your outs yourself, and check the discard pile before you count one.

Keep playing

• Play Gin Rummy against the computer, and try holding out for gin against Hard
• Gin rummy strategy: when to knock and when to wait, tested over 10,000 hands
• How to play gin rummy: the full rules and scoring, with worked examples
• Gin rummy terms, from deadwood to big gin