The GameMaster's Blackjack School
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Lesson 11:Evaluating Games
While almost all Blackjack games are ultimately beatable, the rewards to be gained from marginal situations do not adequately compensate you for your time and risk. Therefore, you must evaluate a game in several ways before playing it. Two primary areas of concern are the house rules of the game, including the number of decks used and the placement of the cut-card, what we call "penetration."
Many rule changes require a change in your basic strategy, so don't forget about the "Basic Strategy Engine" which we linked in lesson 1. Rule changes may also affect your betting schedule, so if you have any doubts about what to do, e-mail me.
Effect of Rule Variations on the Player's Edge
(Assume 6 decks, double on any first two cards, no double after splitting, resplit all pairs, except Aces, insurance is available and the dealer stands on Ace-6. This yields a -.54% advantage to the player.)
| Changes which help the player | Change in the edge |
| Double aftere split | +.14% |
| Resplit Aces | +.07% |
| Early surrender vs. all | +.70% |
| Early surrender vs 10 0nly | +.30% |
| Late surrender | +.08% |
| Single Deck | +.50% |
| Two Decks | +.20% |
| Four Decks | +.05% |
| Changes which hurt the player | Changes in edge |
| Dealer hits A-6 | -.20% |
| Double only on 11 | -.46% |
| Double only on 10,11 | -.09% |
| Double only 9, 10,11 | -.09% |
| No respliting pairs | -.04% |
| No insurance (if you are counting cards) | -.40% |
To determine the casino's edge over you at the beginning of a shoe, just add or subtract the rules variations from the 'base' game listed above. For example, if you play a double deck game which has the same rules as the base game, the casino advantage is computed as follows
| Base game -.54% |
| Two Decks +.20% |
| _____________________ |
| Player edge -.34% |
Effect of Deck Penetration
How far the dealer goes into the deck(s) before shuffling can have a major effect on your winnings. The reason is that with a shallow penetration, the 'high' counts which enable you to bet more occur less often in decks where the shuffle comes early. The table below shows how often counts will occur on a percentage basis at varying degrees of penetration.
| Percent Occurrence at... |
| True Count | 50% | 65% | 75% | 85% penetration |
| +1 | 15 | 15 | 13 | 13 |
| +2 | 8 | 7 | 8 | 8 |
| +3 | 3 | 4 | 4 | 5 |
| +4 | 1.5 | 2.5 | 3 | 4 |
| +5 | 1 | 1 | 2 | 2 |
| +6 | .5 | 1 | 2 | 2 |
| +7 | 0 | .5 | 1 | 1.5 |
| +8 | 0 | 0 | .5 | 1 |
| +9 | 0 | 0 | 0 | .5 |
| +10 | 0 | 0 | 0 | .5 |
Let's examine what I'm trying to say here. If you play at a game with only 50% penetration, out of every 100 hands, only 29 will have, on average, a true count of 1 or better. Since it requires a true count of 1 to get even with the house, only 14 will be hands on which you have an advantage. Now look at the stats for a game with 85% penetration. Here, about 37.5% of the hands will be at breakeven or better and almost a quarter will be hands on which you have an advantage.
YOU ARE WASTING YOUR TIME AND MONEY IF YOU PLAY AT A GAME WITH LESS THAN 65% PENETRATION.
Even if a game doesn't offer the best rules, it can still be beaten if good penetration is available. Remember that you should leave a game when the count drops below a true of minus 1 so that you spend most of your playing time making bets in what I call the 'profit zone.'
Homework
Calculate the player starting advantage for the following:
- Single deck, double only on 10 and 11and the dealer hits A-6. Resplits (except Aces) are permitted and insurance is available.
- Six decks, dealer stands on A-6, double any first two cards, double after split is allowed, resplitting permitted, including Aces and insurance is available.
- Two decks, double on any first two cards, no resplitting of pairs, no double after split allowed, late surrender and insurance is available.
I'll post the correct answers to this quiz next time.
As always, if you have any questions, e-mail me at aceten1@mindspring.com and Ill get back to you ASAP.
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