# How are the odds tilted toward the house in Blackjack? **URL:** \ **Category:** Factual Questions\ **Created:** [June 11, 2004, 8:52pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870 "2004-06-11T20:52:24Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![Bone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bone/32/407_2.png) [@Bone](https://boards.straightdope.com/u/Bone)\ **Post date:** [June 14, 2004, 5:16am UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/21 "2004-06-14T05:16:05Z")
> [@Sam Stone](#): > > In the end, the rules are balanced out to give the house an average of somewhat less than 1% in advantage, making Blackjack one of the best gambles in a casino. Some single deck games with great rules can even give the player an advantage with perfect play (and without card counting). Can you find a cite that shows a 1% or approximate house advantage? I’ve always learned that house edge is aprox 8% using perfect basic strategy (standard Vegas rules). When counting cards using Wong High/Low, you start at a -1% return and go up 1% for each true of 1 increase, thus at greater than true of 1 return goes positive. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 14, 2004, 5:29am UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/22 "2004-06-14T05:29:38Z")
I’m quite sure. The odds in the 4-deck game I used to play (double after split, surrender), was .51%. Six and Eight deck games with average rules are usually around .71% Single deck games with good rules are often around .4% or even less. If the house advantage were 8%, the game would be even worse than Roulette. ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [June 14, 2004, 12:36pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/23 "2004-06-14T12:36:57Z")
> [@Chronos](#): > > OK, I knew that the dealer operated under strict, simple rules (otherwise there’s too much risk of a dishonest dealer helping the players), I just wasn’t sure whether those rules took the players’ hands into account. And I’m aware that you should stand at 15 if the dealer shows 6, but “dealer holding 16” could also be, say, six facedown and a ten faceup (in which case you should hit). You should never hear any strategy that refers to “dealer holding 16”. They should say “dealer showing 6”. This may be assume to be a 16 to a first degree of approximation, since there are so many 10s. This assumption is a useful fiction when teaching basic strategy, so if you hear this from a friend or someone who is glossing over tech stuff, they may say “dealer holding 16”, but it’s incorrect. To extend your example, they may have a pair of 8s, or A-7, which should be played differently. ---
**Author:** ![muttrox](https://avatars.discourse-cdn.com/v4/letter/m/a8b319/32.png) [@muttrox](https://boards.straightdope.com/u/muttrox)\ **Post date:** [June 14, 2004, 12:39pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/24 "2004-06-14T12:39:28Z")
> [@Bone](#): > > Can you find a cite that shows a 1% or approximate house advantage? I’ve always learned that house edge is aprox 8% using perfect basic strategy (standard Vegas rules). When counting cards using Wong High/Low, you start at a -1% return and go up 1% for each true of 1 increase, thus at greater than true of 1 return goes positive. I second Sam. 1% is a good estimate. In fact I believe it’s somewhere even a little better than that… .76% sticks in my head for some reason. According to [Blackjack House Edge - Wizard of Odds](http://wizardofodds.com/games/blackjack/bjhouseedgecalc.html) I get .4953% for the most common casino rules I see ---
**Author:** ![Paul\_in\_Qatar](https://avatars.discourse-cdn.com/v4/letter/p/ccd318/32.png) [@Paul\_in\_Qatar](https://boards.straightdope.com/u/Paul_in_Qatar)\ **Post date:** [June 14, 2004, 4:13pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/25 "2004-06-14T16:13:59Z")
Scarne gives the house advantage as 5.9%. That is the figure I use. ---
**Author:** ![Bone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bone/32/407_2.png) [@Bone](https://boards.straightdope.com/u/Bone)\ **Post date:** [June 14, 2004, 4:27pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/26 "2004-06-14T16:27:34Z")
I stand corrected. I don’t know what I was thinking actually. I knew that you start at about a -1% or so at a True Count of zero, and go up about 1% for each true of 1. I dont know why I would think the non-counting basic strategey True of zero would be different. Ahh well. And to think I counted cards for a 3 years too. :\ ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 15, 2004, 5:45am UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/27 "2004-06-15T05:45:42Z")
**Paul in Saudi** : Paul, that figure is wrong. Honest. It’s generally between .5% and 1%. Scarne was a poor blackjack player, and his basic strategy is wrong. He’s not an authority on blackjack. ---
**Author:** ![Turble](https://avatars.discourse-cdn.com/v4/letter/t/8dc957/32.png) [@Turble](https://boards.straightdope.com/u/Turble)\ **Post date:** [August 18, 2020, 2:50pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/29 "2020-08-18T14:50:19Z")
Typical tourist play turns out to be around 2% because typical tourists make mistakes when they vary from correct basic strategy – like failing to split 8/8, failing to hit soft 18, making incorrect splits, etc. Players who play perfect basic strategy will, in the long-run, come very close to the expected house edge for the rule set they are playing. Interestingly, it turns out that mistakes don’t really matter very much to a basic strategy player so long as his mistakes are random and not due to his misunderstanding his basic strategy chart, making the same incorrect decision repeatedly. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [August 18, 2020, 10:51pm UTC](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870/30 "2020-08-18T22:51:11Z")
That’s actually about what you’d expect. Your average earnings are a function of the parameters of your strategy. For most real-world functions, the extrema (maxima and/or minima) correspond to places where the function’s derivative is zero, meaning small changes to the inputs only make a very small difference to the output. Or, to put it another way: If a small deviation from perfect strategy made it much worse, then a small deviation in the opposite direction would probably make it better, meaning your initial strategy wasn’t perfect after all. [Previous page](https://boards.straightdope.com/t/how-are-the-odds-tilted-toward-the-house-in-blackjack/249870.md?page=1)