The common belief is that a bad player at your table hurts your odds. This simulator tests it directly, by dealing thousands of shoes to a full table and measuring your seat under both conditions. No money, no accounts, no stored data.
You set the table size, from one to seven seats, and the strategy of every seat other than your own. Your seat always plays the published basic strategy chart for the ruleset selected. Each round is dealt to every seat and the dealer, every seat acts in turn, the dealer plays to house rules, and the shoe is reshuffled at the penetration point you set.
The same configuration is run twice, once with every other seat playing optimally and once with every other seat playing typically, so the comparison is the headline rather than a single run. Where you set a mix of optimal and typical seats, that mix is run as a third column.
Typical is not a random error rate. It is a fixed list of published deviations, applied consistently every time the hand comes up, so the profile can be inspected rather than trusted.
| Hand | Basic strategy | Typical play | Published cost | Source |
|---|---|---|---|---|
| Pair of aces against a dealer 10 | Split | Hit as a soft 12 | 2.48 per 10 staked | BlackjackInfo |
| Soft 17, ace and six, against a dealer 7 | Double or hit | Stand | 1.59 per 10 staked | BlackjackInfo |
| Pair of eights against a dealer ace | Split | Stand | 1.28 per 10 staked | BlackjackInfo |
| Soft 18, ace and seven, against a dealer 9 | Hit | Stand | 0.85 per 10 staked | BlackjackInfo |
| Hard 11 against a dealer 10 | Double | Hit | 0.60 per 10 staked | BlackjackInfo |
| Pair of eights against a dealer 10 | Split | Stand | 0.52 per 10 staked | BlackjackInfo |
| Hard 12 against a dealer 2 | Hit | Stand | 0.44 per 10 staked | BlackjackInfo |
| Soft 18, ace and seven, against a dealer 10 | Hit | Stand | 0.37 per 10 staked | BlackjackInfo |
| Hard 12 against a dealer 3 | Hit | Stand | 0.24 per 10 staked | BlackjackInfo |
| Any soft hand the chart says to double | Double | Hit, or stand on a soft 18 | Part of the 0.53 percent total | Wizard of Odds |
| Any hand the chart says to surrender | Surrender | Hit | Part of the 0.53 percent total | Wizard of Odds |
Items one to nine are the playable hands from the BlackjackInfo list of the ten most common basic strategy mistakes, with the published cost per ten units staked in a six deck game where the dealer stands on soft 17 and doubling after a split is allowed. The tenth item on that list, taking even money on a blackjack, is an insurance decision, and this simulator offers no insurance, so it is left out rather than approximated. The last two entries are the simplifications published in the Wizard of Odds simple strategy, whose total cost the Wizard of Odds records as 0.53 percent of turnover.
In a freshly shuffled shoe the order of the cards is already fixed and unknown. Another player taking or refusing a card changes which unknown card reaches you, but every unseen card is equally likely to help or hurt, so the expected value of your own hand against the dealer is unchanged. This holds whether the other player is following the chart or ignoring it.
The one real exception is shoe depletion. Different play at other seats consumes cards at a different rate, which changes how far into the shoe you get before the shuffle and which cards remain when you get there. At a low deck count with deep penetration that effect is measurable, and the simulator reports its size from its own output for the deck count and penetration you set rather than asserting a figure.
Optimal seats read the same structured strategy data as the Blackjack Trainer, generated from the Wizard of Odds basic strategy calculator and the BlackjackInfo basic strategy engine and compared cell by cell. The two sources agree everywhere except a pair of eights against a dealer ace in a two deck game with the dealer hitting soft 17 and late surrender available. Both answers are accepted for that cell rather than one being picked silently.
Not in any way this simulator can measure at normal shoe games. Over thousands of shoes the win rate at your seat moves by a fraction of a percentage point between an all optimal table and an all typical table, which is inside the sampling error of the run. What does change is how many hands you play per hour and how fast the shoe runs down.
There is one honest exception. Other seats consume cards at a different rate, so at a low deck count with deep penetration they change which cards remain before the shuffle. The simulator quantifies that as a difference in rounds dealt per shoe and cards used per round, so the size of the effect is visible rather than dismissed.
The seat acting last is the most visible when a hand goes wrong, so its choices are remembered. The mathematics does not single that seat out. A card taken at any seat has the same effect on what reaches you as a card taken at the last seat.
It costs you hands, not edge. Each occupied seat adds dealing and decision time to the round, so a seven seat table deals far fewer hands per hour than a heads up game. The simulator states the timing assumption used and reports hands per hour for the table size you set.
No. Every seat is a bot, there is no input during a run, results are expressed in betting units, and nothing is stored or uploaded.
Practice hands and see every decision graded against the same chart.
Model bankroll survival, EV and volatility over a session.
See how often a balance is lost before wagering clears.