Evaluating Blackjack Rule Variations for Player Advantage

One of the principal tasks of an educated blackjack player is assessing the various blackjack rule variations and how they affect the house edge. The more the house edge is lowered, the greater is the player advantage. So the goal of a blackjack player is to know what rules are advantageous to him or her and to play where these rules are used. If the rules are very unfavorable in a given casino, he or she will not play blackjack there.

One of the most important considerations in blackjack rule variations is the number of decks played. Most casinos today offer six-deck or eight-deck blackjack. These are disadvantageous to card counters.

Also, remember that blackjack rule variations may require you to adjust your basic strategy moves. Before playing, make sure you get the strategy sheet best suited to those rules.

Blackjack Rule Variations for Player Advantage

These rule modifications are advantageous to the player because they decrease the house edge.

Rule Variation Add. Player Advantage Double after a split +.14% Re-split Aces +.07% Early surrender vs. any cards +.70% Early surrender vs. 10 cards +.30% Late surrender +.08% Single-Deck +.50% Double-Deck +.20% Quadruple-Deck +.05%

Blackjack Rule Variations for Player Disadvantage

These changes in table rules diminish the player's chances of winning and give a bigger house edge.

Rule Variation Less Player Advantage Dealer hits soft 17 -.20% Double on 11 -.46% Double on 10,11 -.09% Double 9, 10,11 -.09% No re-splitting -.04% No insurance (card counters) -.40%

To use these figures, just add or subtract the figures from the base player edge (which is the reverse of the house edge). If the house edge is 0.5%, the player advantage is -0.5%. Add 0.14% if double after split is allowed (-0.36%), subtract .20% if dealer hits on ace and 6 (-0.56%) and so on. The final figure after all rules are accounted for is the net player advantage.

Deck Penetration and Player Advantage

Blackjack rule variations aren't all there is to winning. For card counters, deck penetration is as important.

For the purposes of card counting and shuffle tracking, a deck penetration of at least 65% is desirable, and 75% would be ideal. You can tell what the deck penetration is during a shuffle. Watch where the dealer places the cut card. The deeper it goes into the decks, the higher the penetration. If it's near or on the middle, the penetration is shallow and you should leave the table.

The table below shows how often a true count can be reached on average under specific levels of deck penetration.

True Count 50% 65% 75% 85% +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

Out of a hundred hands played, you can reach a +6 true count an average of .5 times in 50% penetration, 1 time in 65% penetration, and 2 times in 75-85% penetration. If you add up the numbers on each column, you will see that you stand to be on positive true count the most number of times in 75% and 85%. Bottom line? You win more often the higher the deck penetration is.

Avoid penetration of less than 65%. If possible, play at 70% and higher only.

If you find a game has bad rules, look first if it has a high deck penetration. You can still win in it if it does.