Indices please - 8v4, 9v7
- Thread starter UK-21
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my 2 cents
Personally I double 9 vs 7 at TC +4. I dropped indices for 8 vs 4 in my first year of counting. It happens so rarely at the correct count that it isnt really worth that much, esp in 6 or 8 deck games, that I play alot. There is good reason why it's not in the top 18 indices! I do play a few more than 18, but that is not one of them. I suppose if you play a good amount of single deck where strategy weighs more heavily, it may be worth learning.
Personally I double 9 vs 7 at TC +4. I dropped indices for 8 vs 4 in my first year of counting. It happens so rarely at the correct count that it isnt really worth that much, esp in 6 or 8 deck games, that I play alot. There is good reason why it's not in the top 18 indices! I do play a few more than 18, but that is not one of them. I suppose if you play a good amount of single deck where strategy weighs more heavily, it may be worth learning.
Do yourself a favor, learn 30 risk averse plays and forget the other 120. You'll improve your win rate. The gain from RA indices far exceeds the value of knowing stuff like when hard 7 doubles against the dealer's 3.
8 vs 4 @ +8 ??
A +8 count occurs about once every 200 or so hands. The chances of having two low cards for an 8 and the dealer showing a 4 at that 1 out of 200 +8 count??? I would think if you played 8 hours a day, 7 days a week, every day for a year, only taking Christmas and 4th of July off, you would make this play 2 or 3 times. I could be off, you might be able to pick up as much as an extra 4 big bets over the next 29,000,400 hands.
8 vs 4 @ +8 ??
A +8 count occurs about once every 200 or so hands. The chances of having two low cards for an 8 and the dealer showing a 4 at that 1 out of 200 +8 count??? I would think if you played 8 hours a day, 7 days a week, every day for a year, only taking Christmas and 4th of July off, you would make this play 2 or 3 times. I could be off, you might be able to pick up as much as an extra 4 big bets over the next 29,000,400 hands.
8 vs 4 continued thoughts
I also sometimes think that because most counts dont count 7's 8's or 9's that the accuracy is somewhat compromised. I use RPC which counts 7's but still 8's and 9's arent accounted for and who's to say (unless you side count as well) that even though the ratio of high cards to low is up, that whats really in abundance in the remaining cards is 7-9's, any combination of which makes this a losing hand. For that reason I tend to be a bit conservative vs 4. I'm sure this is mathematically wrong. Surely this fact was taken into consideration when considering indices, but I guess thats my conservative nature.
I also sometimes think that because most counts dont count 7's 8's or 9's that the accuracy is somewhat compromised. I use RPC which counts 7's but still 8's and 9's arent accounted for and who's to say (unless you side count as well) that even though the ratio of high cards to low is up, that whats really in abundance in the remaining cards is 7-9's, any combination of which makes this a losing hand. For that reason I tend to be a bit conservative vs 4. I'm sure this is mathematically wrong. Surely this fact was taken into consideration when considering indices, but I guess thats my conservative nature.
Yes, quite understandable. With a dealer 4 at a very high count, the jokers in the shoe will be the 7s which aren't tracked in Hi-lo. On balance of probability, there'll be a sufficient number waiting to pop out to marry up with a probable 10 - leaving the house to clean up on a double max unit bet. I think I shall cast this one into the abyss as recommended.
On a simiar line of thought, would it be prudent to deviate from BS and take a more conservative approach to doubling down against 2,3,4s at higher counts (+5, +6, +7, +8)? Doubling down say a 9v3 is going to carry even a higher risk, bearing in mind the possible conbinations of non counted cards and 10s that could pop out? I think one of those 5 million hand sims needs to be run, where doubling against dealers 2,3,4s is replaced with hitting, to see what the alteration in the EV would be. Anyone up for it? - I don't have the software.
I'm assuming that BS was produced using unadjusted (for the count) mathematical probabilities based on a flat-betting approach. Where play is based on spreading 1-8/16 (with the max bet out at +4) this must have an effect on the level of risk where the BS doubling plays against 2,3,4s are made at high counts? ie the potential cost of losing a double max bet (16/32 units) is greater than the gain of winning the hand on a single unit basis? Am I explaining the dilemma OK?
Newb99
On a simiar line of thought, would it be prudent to deviate from BS and take a more conservative approach to doubling down against 2,3,4s at higher counts (+5, +6, +7, +8)? Doubling down say a 9v3 is going to carry even a higher risk, bearing in mind the possible conbinations of non counted cards and 10s that could pop out? I think one of those 5 million hand sims needs to be run, where doubling against dealers 2,3,4s is replaced with hitting, to see what the alteration in the EV would be. Anyone up for it? - I don't have the software.
I'm assuming that BS was produced using unadjusted (for the count) mathematical probabilities based on a flat-betting approach. Where play is based on spreading 1-8/16 (with the max bet out at +4) this must have an effect on the level of risk where the BS doubling plays against 2,3,4s are made at high counts? ie the potential cost of losing a double max bet (16/32 units) is greater than the gain of winning the hand on a single unit basis? Am I explaining the dilemma OK?
Newb99
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Okay, here’s a shameless plug for k_c’s program.
Now, k_c’s description of his software is a little dry, shall we say? His talk about “shoe state” makes you want to take a nap. It’s actually much more exciting than that. “Shoe state” means you can remove whatever cards you want from the shoe to create whatever count you’re interested in. Then you can find out the EV for any player hand vs. any dealer upcard.
For example, here’s one answer to your question of doubling 9 vs. 3 at a high count (+8). It shows that doubling is still a much better choice than hitting.
Now, k_c’s description of his software is a little dry, shall we say? His talk about “shoe state” makes you want to take a nap. It’s actually much more exciting than that. “Shoe state” means you can remove whatever cards you want from the shoe to create whatever count you’re interested in. Then you can find out the EV for any player hand vs. any dealer upcard.
For example, here’s one answer to your question of doubling 9 vs. 3 at a high count (+8). It shows that doubling is still a much better choice than hitting.
Attachments
Before people start getting off track about uncounted cards, The book "Theory of Blackjack" by Peter Griffin (UCLA math professor and the math authority on blackjack) explains the mathematical proof behind cards that are not counted.
Uncounted cards remain normally distributed, no matter what the "count" is.
In a 6 deck shoe, there are 6 x 4 = 24 8s at the top of shoe. Suppose 3 decks are dealt out. Without counting anything, it is safe to assume there are 12 8s left in the half shoe. HiLo counts the 8 as 0, so it is essentially uncounted.
If the HiLo count was a really high +9? It is most likely there are 12 8s left. If the HiLo count was a really low -9? Most likely still 12 8s left.
The "density" of uncounted cards remains normal.
Also note if you are using KO, where the 7 has 1/2 the value of the other positive cards, in a high negative count KO is only half as effective in predicting a 7 as another low card. So in the classic 14 vs T situation, where 7 is the key card, HiLo is completely worthless for a index, and KO isn't much better.
Uncounted cards remain normally distributed, no matter what the "count" is.
In a 6 deck shoe, there are 6 x 4 = 24 8s at the top of shoe. Suppose 3 decks are dealt out. Without counting anything, it is safe to assume there are 12 8s left in the half shoe. HiLo counts the 8 as 0, so it is essentially uncounted.
If the HiLo count was a really high +9? It is most likely there are 12 8s left. If the HiLo count was a really low -9? Most likely still 12 8s left.
The "density" of uncounted cards remains normal.
Also note if you are using KO, where the 7 has 1/2 the value of the other positive cards, in a high negative count KO is only half as effective in predicting a 7 as another low card. So in the classic 14 vs T situation, where 7 is the key card, HiLo is completely worthless for a index, and KO isn't much better.
Thats an excellent presentation Canceler, however proving that doubling 9 vs 3 at a high true count of +8 is a bit different than newb99's original question concerning 8vs4 and 9vs7 indicies. Doubling 9 vs 3 is a basic strategy play after all. So naturally at a high count of +8 it would be a much better choice. 8vs4 of course is not basic strategy, nor is it in the Illustrious 18. Thus the question, at what point does it become the better choice to double? I personally have seen numbers varying from +6 to +10 from several different, what I consider knowledgable sources. And then the secondary question arises, Is knowing this even worth the time and effort involved, given the infrequency of the play at the correct count. This of course is a more personal choice. However, if you answer no the the second question, the first becomes mute, and you can focus your time and energy elsewhere.
It depends on your aversion to risk. Some people will double at the first sign of a higher EV (despite the higher risk) while others will wait for a higher EV before doubling their bet. The value of the index will depend on many factors that may be different for each player. It is based on the bet size at each count and the value of the player's certainty equivalent. Different people use different bet spreads and may have different tolerances for risk. That is why an index number, especially a “dangerous” one like doubling 10 vs. 10, can vary from +4 to +8 or more. Technically, any of those numbers are correct depending on what factor you are optimizing for.
-Sonny-
-Sonny-
IMO anytime you give up an index which is mathematicly proven to give you an advantage and revert the play to BS, you give back the advantage you are working so hard to gain.
I'll fight for every last dollar I can win. The only time I refrain from the higer index plays is within the first deck from the top of a shoe.
BJC
I'll fight for every last dollar I can win. The only time I refrain from the higer index plays is within the first deck from the top of a shoe.
BJC
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Not entirely true. Some of these deviations, although +EV, also increase variance. Increased variance means an increase in risk. So if you are betting optimally, your bet sizes will be smaller with the same bankroll and same comfortable risk of ruin factor.
If you do not take risk or variance into consideration, then the optimal bet is to bet your entire bankroll as soon as you have the slightest advantage. Taking risk into consideration, you calculate your variance and place bets that increase with the % of advantage/variance.
Doubling indexes increase variance. The mathematical +EV index for 8 vs 4 is +6. The risk adverse index is +8.
By using risk adverse indexes, although you are giving up some +EV, you are lowering your variance and risk, so with an equal bankroll and the same risk of going bust, you are making larger bets overall at most counts. You win more money in the long run, even though you are not "getting everything you can".
If you do not take risk or variance into consideration, then the optimal bet is to bet your entire bankroll as soon as you have the slightest advantage. Taking risk into consideration, you calculate your variance and place bets that increase with the % of advantage/variance.
Doubling indexes increase variance. The mathematical +EV index for 8 vs 4 is +6. The risk adverse index is +8.
By using risk adverse indexes, although you are giving up some +EV, you are lowering your variance and risk, so with an equal bankroll and the same risk of going bust, you are making larger bets overall at most counts. You win more money in the long run, even though you are not "getting everything you can".
This is also correct. The frequency of 8 vs 4 occuring at a +6 or +8 count and you actually using this index, means you will not even make an additional 1 cent an hour even if you are playing $100 a hand.
I think some guy named Don or something came up with a list of 18 or 20 indexes that capture almost 80% of the profit possible. You can probably add 10 or so more on to that simply because the numbers fall into place and they are easy to remember.
Your time is probably better spent learning the adjustments to make for that limited number of indexes for S17/H17 games, double deck vs shoes, etc. so if you find a good game that is not your normal rule set, you still can do a good job of beating it.
I think some guy named Don or something came up with a list of 18 or 20 indexes that capture almost 80% of the profit possible. You can probably add 10 or so more on to that simply because the numbers fall into place and they are easy to remember.
Your time is probably better spent learning the adjustments to make for that limited number of indexes for S17/H17 games, double deck vs shoes, etc. so if you find a good game that is not your normal rule set, you still can do a good job of beating it.
If thats the case, then you've taken the time to learn several hundred indices for each different games, H17, s17, 6 decks, 2 decks, single deck, das, no das, donly 9,10,11, that you may encounter. You also spend every second at the table calculating and remembering indices (when should I double a hard 5 vs 6 again? hard to remember since it hasnt come up at correct count in several years of actual play) and most probably making errors. When someone asks the score of last nights game, you blurt out +5! :laugh: You have also been so busy you haven't noticed the pit lady on the phone staring at you, or been able to casually notice the count of the game next to you has soured to +14 after only 2 rounds. (a missed opportunity) but at years end you will have fought for and won every last dollar, or more likely cents, assuming your errors didnt wipe out such.
Now now gents . . . .
The question that fell out of my original post (sorry I meandered off topic slightly) was really about whether continuing to double against small cards (2,3,4s) at very high counts remained a prudent move or not, and whether the risks posed by the 7,8,9s still in the deck (in pairing up with a 10 to the up card) were such that it would be better not to throw another 8 or 16 units out on to the felt in exchange for a single further card. The cost of losing the hand after doubling one unit is a lot less than when doubling a max bet.
The consensus looks to be that it is.
Many thanks for the contributions.
Newb99
The question that fell out of my original post (sorry I meandered off topic slightly) was really about whether continuing to double against small cards (2,3,4s) at very high counts remained a prudent move or not, and whether the risks posed by the 7,8,9s still in the deck (in pairing up with a 10 to the up card) were such that it would be better not to throw another 8 or 16 units out on to the felt in exchange for a single further card. The cost of losing the hand after doubling one unit is a lot less than when doubling a max bet.
The consensus looks to be that it is.
Many thanks for the contributions.
Newb99
That was very good, LMAO...:laugh:
Playing 99% of the time at 6-8 deck, s17, das, I studied only the indices that I need for the game I play which is approx 80. The funny part is my wife asks me all the time how I can keep track of the count and the play when I talk the entire time to the delar, players, pit crits and waitresses. I just need to improve my discipline which seems to fluctuate as my adrenaline rises. It must be all the beauties walking through the casino today with the high skirts.. Makes me grab a stack of green and black a bit too often.
Playing 99% of the time at 6-8 deck, s17, das, I studied only the indices that I need for the game I play which is approx 80. The funny part is my wife asks me all the time how I can keep track of the count and the play when I talk the entire time to the delar, players, pit crits and waitresses. I just need to improve my discipline which seems to fluctuate as my adrenaline rises. It must be all the beauties walking through the casino today with the high skirts.. Makes me grab a stack of green and black a bit too often.
glad you enjoyed that Bjcount. Wasn't being confrontational, just a discussion offering a different, most likely erroneous view. You are right about discipline. That is key to this game. Especially when dealing with the low skirted beauties.:laugh: They can do more damage to your bottom line than playing through negative shoes.!!