When to Knock in Gin Rummy
You may knock in gin rummy whenever your deadwood is 10 or less after discarding. Knocking can be the right play, but it isn't always. The question every turn is: will I score more by knocking now, or by waiting?
The case for knocking early
- Your opponent's hand is weakest early. After two or three turns they usually still hold 30 points or more of deadwood, so even a 10-point knock scores well.
- Undercuts are rare early. To undercut you, your opponent needs less deadwood than you, which takes time.
- Each turn is a risk. Waiting lets your opponent draw into their own knock or gin.
On kawu, the normal computer knocks early with any legal hand.
The case for waiting
- Gin is worth 25 more and blocks layoffs.
- Late in the hand, your opponent's deadwood has dropped. A knock with 8 or 9 then often gets undercut, which costs you their difference plus 25.
The normal computer only knocks later in a hand when its deadwood is small (6 or less, then 3 or less near the end of the stock).
Read your opponent
What your opponent picks up and throws away is public:
- They picked up several cards from the pile: they're building melds. Their deadwood is falling, so knock sooner, not later.
- They're throwing high cards: they're reducing deadwood and may be close to knocking.
- They keep drawing from the stock: the pile isn't helping them, so their hand may still be loose.
The hard computer uses this information. Before knocking, it deals out dozens of possible opponent hands consistent with what it has seen and knocks only when the expected score is positive and the chance of being undercut is low.
Count layoffs
Before you knock, look at your melds from your opponent's side. An open-ended run like 5-6-7♦ invites the 4♦ and 8♦; a set of three invites the fourth card. If your opponent has picked up a card that fits your meld, assume they can lay it off.
A simple rule of thumb
| Stage of the hand | Knock with |
|---|---|
| First 5–6 turns | Any legal knock (≤ 10) |
| Middle of the stock | 6 or less |
| Last third of the stock | 3 or less, or go for gin |
Adjust for what your opponent has picked up, and for the score: when you need only a few points to reach 100, a safe small knock is worth more than a risky gin.
Frequently asked questions
Should I knock as soon as I can?
Early in a hand, usually yes: your opponent's hand is still weak, so an undercut is unlikely. Later in the hand, knock only with low deadwood.
Is it worth waiting for gin?
Gin is worth 25 extra points and can't be laid off against, but every turn you wait gives your opponent a chance to knock or improve. Wait only if you're close to gin and it's still early.
Last updated 2026-10-17