Surrender always, if surrender is available. (16 vs 10). It's a loser and as the count goes up, it becomes a more probable loser. It already loses more than 50% of the time at a count of zero, and as the count goes up, so does the dealer's winning percentage.
Surrender indices (I assume you are using the fab-4 along with the I-18) for 16 vs 9, 10 and 11 are "always surrender" if it is available). 15 vs 10 is +0, and 15 vs 9 or A is +2...
Norm- A "New Thread" it's called.....When you get to the forum click on blackjack strategy and this will get you to the current page of posts. Then at the top click on New Thread which will force you to login and then takes you to a new thread page.
If you edit a post, that is a little different also (save), plus a few other small things.
There is another opinion. When no surrender, hard 16 against 9 is nearly an automatic loser against dealer's 9 but some players hit when deck is -5 or below based on might pick up 3-4-5 and push or win a hand now and then.
first, for 16 vs 9. Stand, your ev is -.54, which is why surrender (-.50) is a better play. Hit is -.51, still worse than surrender, but better than standing.
the 16 vs 9 index play is hit at +4 or less, stand at +5 or higher. So yes, you would hit at all negative counts, but even at 0, +1, +2, +3 and +4 it is still the right choice EV-wise...
I'm no expert, either, but I play two and three card totals the same until otherwise instructed. SSR pretty well nailed it by the numbers. (I'm weak on surrender options and probably ought to do something about that.) SSR is saying hit anything below +4 which is, imho, pretty darn ten rich. You don't hang in the +5, +6 area very long. The system so much as tells you that when you hold 16 vs 7-A you have pretty well had it. You're in a damage control mode, that's my point. Remember, you stand vs 10 at +0. That's a four count swing from the vs 9 play. It's saying if there are 10s in the deck, hit vs 9 but stand vs 10. Go figure.
We are mixing apples and oranges. 3 card 16s only mean something to a non-card-counter. They are called "composition-dependent playing decisions" because a 3 card 16 slightly increases the count since it takes at least 2 small cards to produce that total.
But a counter knows more. Say the count is -5, and you get a 10-3-3 vs a dealer 9. Do you stand or hit? A counter will _always_ hit that hand, because he knows there are 5 more small cards per deck left than big cards.
_always_ play the index play.
I'm not aware of any "stand at 0" (Hi-Lo) index play for 15 vs 9. I gave the number right out of Won'g Pro BJ book a reply back. Now if you are talking "unbalanced count" such as red-7 or kiss, then that makes a difference because of the pivot issue... I always give Hi-Lo numbers (the most common counting system in use today).
ESS:
the indices are derived from billions of rounds of simulation. While to you (or others) a 3 card 15 might seem worse than a 2 card 16, it isn't. 16 is the worst thing you can get, as you have two ways to win. Hit and beat the dealer, or let the dealer bust. With a 10, the dealer is likely to make a winning hand, more-so in high counts since that hole card is likely one of those extra 10's we know about. The 15 is not as bad as 16, because when you hit the 16, you have 5 cards that will help you, 8 that will break you. With the 15, that becomes 6 and 7, which is significantly better odds of making your hand than with the 16.
When you are thinking about all of this, think probability. And the simple approach is to think "there are 13 cards (A-9, 10, J, Q, K). Out of those 13 cards, how many wlil help and how many will hurt. That will be your probability of helping or hurting your current hand. For example, "always hit soft-17". To make it better, you need an A, 2, 3 or 4. The 4 10's don't change it at all. So 5 cards make it worse, 4 make it better, 4 don't change it at all. Hitting is worth the chance. You have a five out of thirteen chance of improving it, and since a 17 is generally a loser, hit is correct. All because of the 13 different card values. Now of course a counter might know more. For example, the count is +4, so we have 4 extra 10's per deck. Or you subtract 2 small cards and add 2 10's. Now our probabilities change. Since our deck now holds an excess of 10's over a normal deck, our probability of drawing a ten becomes 5 out of 13 rather than 4 out of 13. Of course, our probability of drawing a 2-6 becomes 4 out of 13 rather than 5 out of 13. So we know more, we can compute a more accurate probability based on the remaining deck composition, and make a more accurate playing decision.
The math is not really that complicated, and while it can make your head explode at times, the basic ideas are built around that 1/13 chance of drawing a 2 thru A in a neutral deck, and how that swings as the count changes.
Yeah 17 is a dog... figure to lose 40%. And its really bad against an Ace. If the dealer hits soft 17, even the chances of a tie are remote, and surrender is the play.
Actually, you're not off base too much at all. It does depend upon wether Late Surrender is offered, as one would surrender 16 vs. 10 and 9, but with 3 or more cards in the hand, surrender is not an option. While 2-card 16 vs. 10 is a 51% loser, 3-card 16 vs a 10 is a 53-54% loser, but so is stand... thus the Hobbs' choice.
For Basic Strategy, this is complicated... splitting hairs. For Advantage play, its simple... ZERO or + stands.
But 3-card 16 vs. 9 and 15 vs. 10 can only be figured using advantage play. We all know hitting these dogs is like slapping Grandma, but its just a little better than standing.
It's saying if there are 10s in the deck, hit vs 9 but stand vs 10. Go figure.
I guess the chance of you getting a 4 in addition to the 5 will give you the best hand over a dealer's 9(teen).
On a slightly different subject, answer me this. Why does a basic strategy chart tell you to hit 16 vs 10, but i18 tells you stand TC>=0.
I always believed that a basic strategy chart was simply the best strategy for a straight 0 count. For example, if you were going to play against a CSM, there would be no need for i18, you could only use BS because the count is 0 each hand.
" On a slightly different subject, answer me this. Why does a basic strategy chart tell you to hit 16 vs 10, but i18 tells you stand TC>=0 ? "
Basic Strategy is an absolute yes/no decision based upon the cards in your hand and the dealer's up-card. It DOES NOT take into account the previous hands, or the other player's cards at the table this round... just you and the dealer. Since there is no score-keeping the cards are not tracked, and the game is played as a "score" of exactly ZERO all the time, every hand one plays.
The i18 like other advantage plays indicate a score-keeping method. Usually + for small cards and - for 10's and Aces. An index such as ZERO in your example is NOT an exact value... rather its a range of running counts / # of decks that rounds to ZERO. Thus ZERO occurs with both a + and - running count. In your example, the + running count has a slightly stronger effect than the - , and the decision is therefore STAND.
I should keep my mouth shut until I dig out the books. I'm going by an old scratch sheet that's a combination of Wong, Revere, and Thorp. I assume these talks relate to the hi-lo as in Wong.
My sheet says 16 vs 9 is a H below +5. You might as well say it is a H. The richer in 10's, the more likely the dealer's 9 up is a 19. Also, the richer the 10's, the more likely player will break the 16. The moral is, with 16 vs. 9, the higher the count, the worser it gets. Also, the higher the count, the more likely the dealer has one of those 10s. This is one of those hands where it would be a big help to track the 5's, but how many players can do that? It's 7/13 the dealer stands and wins with 9/8-A. Or, he's got 2 and you're still in trouble.
Taking a card is a minimal gain at best; 5/13 to even improve the hand, and, practically, only 3-4-5 is much use. Common sense tells you to hang around for one of those 5/13 that the dealer has 13-16. Still, IBM says H and H right up through +5.
There have been trials run that show the gains and losses for each play and I'd be willing to bet this is one of those minimal gains. Nevertheless, there are only about 17 instances (not counting DD and SP instances) to put knowledge to work for the player, and this is one of them.
Does that scratch sheet also indicate surrender of 88 vs. 10's at +1 or +2 ? This is usually left out by some of them, and should be added if not present.
N 'n B: When I first learned BS, surrendering was not in the air as it is now. Surrender 8's vs 10 above +1 is an easy enough learn.
I always find it easier to make the play when I can get a handle on the "reason" for it. This is one of those plays where the small cards are going to really hurt the player, since he's about to H two 8 hands.
I wonder how close the numbers come to having the player do the same thing against an A ? The same reasoning would apply, would it not? As you well know, most of the BS experts knee jerk "split all 8's," saying little of surrender.