Is Q-6-4 really the right rule in 3-card poker?
Yes. Play Q-6-4 or better and fold anything lower. The rule is exact: it gives the best decision for every one of the 22,100 hands, on every ante bonus paytable.
Playing Q-6-4 is worth −0.9934 per unit of ante against −1.0000 for folding; playing Q-6-3 is worth −1.0026. Following the rule you play 67.4% of hands.
The hands around Q-6-4
Your hand
| Your hand | Play | Fold | Best |
|---|---|---|---|
| K♣ 3♦ 2♥ | −0.5515 | −1.0000 | Play |
| Q♣ 7♦ 2♥ | −0.9757 | −1.0000 | Play |
| Q♣ 6♦ 5♥ | −0.9866 | −1.0000 | Play |
| Q♣ 6♦ 4♥ | −0.9934 | −1.0000 | Play |
| Q♣ 6♦ 3♥ | −1.0026 | −1.0000 | Fold |
| Q♣ 6♦ 2♥ | −1.0124 | −1.0000 | Fold |
| Q♣ 5♦ 4♥ | −1.0210 | −1.0000 | Fold |
| J♣ 10♦ 8♥ | −1.1407 | −1.0000 | Fold |
Average result per unit of ante, ante bonus (5/4/1) included and pair plus left out, against all 18,424 hands the dealer can hold. Folding always loses the ante: −1.0000.
Why
Folding costs your ante. Playing puts up a second unit, but the dealer fails to qualify about three times in ten and then your ante wins whatever you hold, which is what makes weak queens worth playing. Q-6-4 is the hand where the two choices cross: a hair better than folding. Q-6-3 is a hair worse. Every hand with a higher card, a pair or better is clearly a play.
Does the ante bonus paytable change it?
| Ante bonus (straight flush/trips/straight) | Weakest hand to play | Strongest hand to fold |
|---|---|---|
| 5/4/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 4/3/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 3/2/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 5/3/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 9/8/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 12.5/10/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 50/10/4/3/0 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 50/50/8/6/0 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |
| 10/10/5/4/1 | Q♦ 6♣ 4♣ | Q♦ 6♣ 3♣ |