Correct BS for pair of 9's vs. Ace in SD, H17 game??

I'm heading to Reno Thursday and am planning on playing the abundant SD, H17 games. I'm in the process of memorizing the proper basic strategy, which is somewhat different than the DD, S17 strategy that I'm used to using in Indiana. I've noticed just 1 difference in the BS charts posted on 2 very reputable websites. Wizardofodds.com says to always split 9's vs. Ace, but blackjackinfo.com says split only if DAS is allowed (which it is not in Reno SD games). Does anybody know which one is correct?

I haven't looked at the websites you mention, but splitting nines against an Ace is a no-no in any basic strategy of which I am aware. There are index numbers for that play, but we are talking basic strategy here. If those sites are giving that sort of advice, I'd be leery of anything else they say.

Splitting 9s vs a Reno Ace has a relatively low index number. It is low enough that it is probably Counter Basic Strategy. This would mean that, if a you were not going to learn an index number for the play, then you would always Split rather than always Stand. This is especially true in Single Deck or with DAS.

I don't think this is what those Websites were talking about. But the idea is really not off-the-wall.

I just did a little thumbing through some of my BJ books. Thorp, Revere, Uston, Wong, Snyder, Vancara & Fuchs, and Carlson all agree that 9's should be split against everything except 7, 10, and Ace, regardless of rules or number of decks.

I'd call that a consensus.

Since you have Griffin handy, could you post the percentages?

I wonder why all the other authorities say otherwise? About half of the references I mentioned above were "generic" strategies, which would explain it, but the others were specifically for "single deck, downtown rules," which would imply H17.

I also wonder why I haven't seen this discussed before? I cannot imagine that no one has previously noticed this discrepancy.

If I recall, it is +1 with DAS and about +2 with no DAS. Still not BS though.

The great Peter A. Griffin clearly explains this in his cascading basic strategy chart preamble (including use of the pair-splittin' algorithm, whatever that is). I think there is one other composition dependent change vs. total dependent basic strategy. I think it is splittin' 3's against a dealer 8 in a two deck game. Could be wrong about that, however.

The exception to the rule in Griffin is for the DAS game. It did surprise me though. Wong's Appendix E in Professional Blackjack gives the expectation for splitting on a single deck H17 game as -.193 for no DAS and -.186 for DAS, while showing a -.187 for standing. Close call and maybe a good cover play.

nt

Splitting a pair of nines isn't my idea of composition-dependent BS. No one would consider 9-9 an 18. It belongs to the group of BS decisions we consider to be "the pair splits." To me, this isn't the same as c-d BS, where, when I have a 12, I worry about which cards I have in my hand. I hope you see the difference.

In any event, I'll go out on a limb and say the following: if you read it on Mike Shackleford's brilliant thewizardofodds.com site, it is correct. And, the fact that he agrees with Griffin cements the deal. Others who disagree? Too bad for them!

Don

For an increase in EV of .001, we are going to throw twice as much money out on the table?

I think not.

Note that I am not disputing the numbers, and certainly not arguing with Griffin, but I question the wisdom.

This looks to me like a classic example of what "risk-averse" strategy is all about!

Since the decision we are discussing is stand vs split, we are obviously talking about a pair of 9's, and not just any 18.

Just how many different compositions can a pair of 9's have? :-)

Guess I am forced to agree with you, if when you have 6-6 you make a pair-splittin' decision before making a basic strategy decision. For instance, 6-6 vs. 2 or 7. Right, DS?

I think I have that right. The good thing for a counter is to have an index number and avoid confusing himself. I think.

Arrogant me.I thought I knew it all.

I guess it was obvious to everyone but me that all pair-split decisions are composition dependent by definition.

you should split, except if you can split only once. DAS makes no difference in the decision.

Shackleford disagrees with Griffin according to the above posts about Griffin's book. The SD, H17 BS chart on Shackleford's site (www.thewizardofodds.com) indicates that you should always split 9's vs. Ace, whereas Griffin says you should only do it if DAS is allowed. So, if the above posts about Griffin are correct, Ken Smith (www.blackjackinfo.com) is the one who agrees with Griffin. I've also found another site (www.bjmath.com) that agrees with Smith and Griffin in saying that you should only split if DAS is allowed.