The Cut Card Effect in Blackjack

7 June 2020

By John Grochowski

QUESTION: I recently heard of something called “the cut card effect” that raises the house edge a little when a cut card is used in blackjack.

Why would that make any difference? Isn’t the proportion of the cards the same? Does it apply to online blackjack?

ANSWER: Last question first: Most online blackjack games have a fresh shuffle for every hand. Cut cards are not used, so the cut card effect does not apply.

Now, then. I’m not going to pretend to be an expert in this aspect of blackjack. I’d suggest that serious player who want to explore the effect read Michael Shackelford’s essay at https://wizardofodds.com/games/blackjack/cut-card-effect/

But at a basic level, the theory is that using a cut card tends to increase the number of hands played with a high concentration of low cards and decrease the number of hands played with a high concentration of high cards.

A high concentration of high cards works in favor of players. More blackjacks are dealt and you’re more likely to draw 10s on your double downs if the deck is rich in high cards.

The blackjack house edge calculator at wizardofodds.com lists house edges about two-hundredths of a percent higher with a cut card than without. In a six-deck game in which the dealer hits soft 17 and a common collection of double and split rules, the calculator comes up with an edge against a basic strategy player of 0.639 percent with a cut card, or 0.619 percent if a continuous shuffler is used.

Think of it this way: High concentrations of high cards are a result of an excess of low cards already having come out on previous deals.

Hands made up of a lot of low cards consist of a higher than usual number of cards. As those low-card hands are dealt, they take you ever closer to the cut card. So hands favoring the player with a wealth of high cards can be cut short by the cut card.

On the other end, high cards use fewer than an average number of hands to make up a hand. If early hands are high-card rich, the remaining deck has a high concentration of low cards. It takes time to balance out the early run of high cards, so a long run of low-card dominated, house-favoring hands can take you up to the cut card.

If a set number of hands were played instead, the effect would disappear. Sometimes, with a flurry of high cards, you’d reach the set number of hands early, before a cut card. Sometimes, if low cards came out early, a set number of hands would take you past the cut card and give the high cards a chance to come out.


QUESTION: The first time my mother ever played in a casino, she won a slot jackpot for $10,000. Needless to say, she’s been a slot fan ever since

The first time my sister ever played, she was losing at slots but tried video poker and draw a royal flush for a progressive of more than $1,100.

The first time I ever played, I lost $200 and hardly got any bonuses, leave alone jackpots.

So what’s wrong with me? (P.S. I still play, and have fun. I’ve hit a few jackpots in 12 years, but alas, no beginner’s luck.)

ANSWER: Not a thing. Days like yours happen. I’m glad you’ve had some better days since.

Nothing in the games would change odds and percentages for a beginner. If you’re trusting luck, your mileage may vary, as you found out.