How Bad Are Common Departures from the Blackjack Gospel?

To tag the long-term effects with actual percentages and dollars, assume an eight-deck game with liberal rules. And pretend that a player bets an average of $25 on one spot, at a table with three other positions in action. The house advantage for flawless Basic Strategy is just under 0.44 percent; the casino's theoretical earnings from this bettor in a four-hour session are $37.

Even some good players bumble soft doubles. Basic Strategy is to double on A-6 and A-7 against the dealer's three through six, on A-4 and A-5 facing four through six, and A-2 and A-3 when the dealer shows five or six. One extreme violation is to double on everything from A-2 through A-7 versus two through six. The total rise in edge is a scant 0.05 percent, an expected average cost of $4 for the four hours. The converse breach, hitting soft hands calling for doubles, seems more benign but anticipates increases of 0.12 percent in edge and $10 in average theoretical casino profit for the four-hour exercise under the supposed conditions.

A situation that's frequently thought to separate masters from muddlers is 12 versus two- or three-up. Hitting is dogma but bezonians tend to stand. Doing so costs a slight 0.04 percent in edge, $3 projected difference after four hours under the sample circumstances. Likewise, the book says to hit A-7 against nine, 10, or ace but lots of solid citizens stand. The price they pay is only 0.02 percent on edge and an expected $1 after four hours.

You see doubles on hard eights once in a while. This, for all dealer upcards from two through six, increases house advantage by 0.09 percent and represents a theoretical out-of-pocket cost of $17 for the person in question. Making this imprudent play only when the dealer is weakest, showing a five or six, sacrifices 0.02 percent in edge and something over $1 in theoretical return.

How about all those times you cursed someone at the table for hitting rather than splitting a pair of eights against a high dealer up-card? The damage for this infraction against any nine, 10, or ace is a mere 0.02 percent in edge and about $1 in the pelf the bosses expect to pocket after four hours. Standing on hard 16 against a 10, another decision that drives doyens up the wall, amounts to under 0.01 percent in edge and less than $1 in every four hours under the presumed playing conditions.

A few suboptimal moves do have strong repercussions. Always taking insurance is extravagant, adding 0.29 percent to the house edge and $24 to its four-hour theoretical proceeds. Insuring only blackjacks is less significant, simply because the opportunity to do so occurs less often. The penalty is a bit over 0.01 percent in edge and under $1 in theoretical four-hour player loss.

Hardly any players split pairs of 10s but many wonder about it. Bad idea! This split can "work," of course. But, against two through six, it ups the edge by 1.49 percent and anticipates a $125 forfeiture after four hours in the proposed game. Adding dealer sevens and eights to the mix raises the edge and theoretical cost by another 0.96 percent and $80, respectively.

Over huge numbers of hands, common departures by patrons from optimal play become big bucks on casino balance sheets. During a single session or casino visit, however, their influence on an individual's performance is small. Negligible, even, owing to the dominance of volatility over edge for statistically short games. So, recognize that you maximize potential winnings at blackjack by following Basic Strategy. But neither be too quick to condemn those who make the "usual" weak plays, nor overly upset when you're getting hammered and some clueless dilettante is raking in the dough. For, as the beloved bard, Sumner A Ingmark, wrote:

Those who know rules without comprehending them,
Often are doomed to overextending them.