Bolder Doubling under DDR!?

[Jess]

For my initial education I have used both the Basic Strategy Engine and the Strategy Trainer at blackjackinfo.com!:)

Unfortunately, you cannot set these to employ the double down rescue rule and learn! I understand that under this rule one may double some hands that otherwise shouldn't be doubled, e.g., 11 against T and A. However, I wonder if it wouldn't be worthwhile to make a more extensive use of the DDR and also double 9 against 7 or 8, double some more soft hands, etc.

My question is: how (where) can I learn more about basic strategy under the DDR rule?

Thanks!:)

[Hsiaodi]

Are you playing bj or sp21? Where are you playing this game?
There are very few times that you don't double 11 against 10.....

[RenewableBP]

9 vs 8




Hit EV is 9.8% (http://wizardofodds.com/games/blackjack/appendix/1/)


If you double:


9 + A -> 20, EV 158%
9 + K -> 19, EV 118%
9 + Q -> 19, EV 118%
9 + J -> 19, EV 118%
9 + T -> 19, EV 118%
9 + 9 -> 18, EV 21%
9 + 8 -> 17, EV -76%
9 + 7 -> DDR so EV -100%
9 + 6 -> DDR so EV -100%
9 + 5 -> DDR so EV -100%
9 + 4 -> DDR so EV -100%
9 + 3 -> DDR so EV -100%
9 + 2 -> DDR so EV -100%


Average above you get -2%. -2% is worse than 9.8% from hitting, so hit is better. In theory you can follow this approach but it gets tedious real quick. I have some more in a spreadsheet if you want.










Dealer outcome with 8 upcard. (http://wizardofodds.com/games/blackjack/appendix/2a/)


17 -> 0.128846
18 -> 0.3598
19 -> 0.128684
20 -> 0.069263
21 -> 0.069452
bust -> 0.243954