top 5 bs changes

What are the top five (i.e.: have the most effect on your bankroll) deviations from basic strategy? I hear surrender 15 & 16, 15 & 16 vs dealer 10, and 12 vs dealer 2 & 3?

followed by 16 v 10, and 15 v 10 (NSR games). Not sure where the surrender indexes stack up, but I think you gave the most significant of those.

Also, do you still always split aces when you cannot resplit them and only get one card for each ace? (6D game). If not, whats the right play?

I don't know what the index number is for this play

...I believe he mentions that 16 v T takes precedence over insurance in shoe games...just a note.

ANS

Do not split aces against a dealer ace if you will lose both bets to a dealer blackjack - hit instead. This is the only time I can think of when you wouldn't split a pair of aces.

I don't have Don's book handy, but I know he had insurance as #1, although he was not addressing a specific game. I thought insurance was #1 by a longshot in general, but I may be wrong. Unfortunately Don does not post here. Maybe someone else has the definitive answer.

Griffin's work analysis was for flat-betting, and assumed perfect play.

Don's work was for using a spread, and playing High-Low.

This is why they have different results.

Personally, for 16v10, I think we think about it the wrong way. The baseline strategy for it should be to Stand. When we examine the importance of the index, we consider hitting 16v10 in a negative count. The gain from hitting it is relatively small.

Thank you for the clarification MP. A further comment on your point about 16 v T. T-Hopper's THBS does exactly what you allude to, and dictates standing.

ANS

Blackjack Count Analyzer will calculate these for you for any betting and counting system and any set of rules. I just returned from a trip to Vegas and calculated using $25-75 spread at single and double and $10-60 at 6-deck, hi-lo count.

At single deck, insure at 1 is far and away the most valuable, with EV (x100) of 16.045.
hard 12 v 4, stand at 0 and above, ev1.472
hard 13 v 2, stand at 0 and above, ev1.471
hard 16 v 10, stand at 1 and above, ev1.262
hard 12 v 3, stand at 2 and above, ev .551

Double deck insures at 2 for ev 8.832
12 v 4, stand at 0, ev1.450
16 v 10, stand at 1, ev1.207
11 v A, double at 0, ev1.169
9 v 3, double at 0, ev .606

I wasn't happy with my 6-deck chart because it told me to stand on a 16 against a 10 instead of surrender. This may be right, but it was not what I expected. Anyway, here are my numbers

Six deck
15 v T, surrender at 0, ev2.937
Insure at 3, ev2.733
13 v 2 stand at 0, ev1.197
12 v 4, stand at 0, ev .962
16 v T, stand at 1, ev. .895

The program is quite good, although I do not like the game module. I find it helpful to deal a few million hands to see where the breaking points are in a game. And the top 20 strategy deviations is quite helpful, although you will quickly see that you only need the top five or 10 to get the most effect.