This system, named for the mathematician J. L. Kelly, is much
more complex than the system we learned earlier but it is much
more efficient. This system dictates that the player should bet
the percent of his bankroll that corresponds to the probabilistic advantage you have on that hand. If your bankroll is $1,000
and you have a 1% edge, you will bet $10. If you have a 2.5%
edge, you will bet $25.
This system relies on knowing your edge at any point in the
game. This can be calculated using the following formula:
edge = expectation + ( 0.5 * real count)
We did not talk about expectation in this book but it represents
the player's expectation of a win if following basic strategy
and it is dependent on the rules of the casino. A player who
follows basic strategy in a single deck game where the dealer
stands on soft seventeen, doubling down is permitted on any two
opening cards (but not after splitting) and there is no surren
der will have an expectation of 0%. He will be even with the
house. Use the chart below to get an idea of your expectation
based on rule differences.
Rule Variation Impact on Expecta
tion
Early Surrender* + 0.62
Late Surrender ( 1 or 2 decks ) + 0.02 Late Surrender ( 4 or more decks ) + 0.07
Doubling on three or more cards* + 0.20
Drawing more than one card on split A’s* + 0.14
Doubling on split pairs + 0.10
Re-splitting of A’s + 0.03
Re-splitting of pairs + 0.05
No doubling on 11* - 0.89
No doubling on 10* - 0.56
No doubling on 9 - 0.14
No doubling on soft hands - 0.14
Two decks - 0.38 Four decks - 0.51
Six or more decks - 0.60
Dealers hits soft 17 - 0.20 *Rarely found these days