H17 games

assume_R

Well-Known Member
#1
Is the reason that H17 games are so much worse because if the dealer gets a soft 17, then hitting will on average yield a higher total? But won't the bust rate increase also? Anyone know the math for this?

-AR
 

21forme

Well-Known Member
#2
I don't have the numbers handy, but 17 is a losing hand. For example, if there was a casino promo offering you have a 17 every hand without drawing any cards, you would lose. Believe it or not same is true about 18, though 18 is a close call. Tthe "neutral" point is actually 18.2. So what's the best thing to do with a losing hand? See if you can improve it. Sitting a soft 17 will improve the hand more often than not (though when we do it, it doesn't seem that way, does it? :eek: )
 
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Sonny

Well-Known Member
#3
assume_R said:
Is the reason that H17 games are so much worse because if the dealer gets a soft 17, then hitting will on average yield a higher total?
Right. The dealer bust rate will increase but only slightly for certain upcards (the ace is a notable exception). The probability of reaching a 17 decreases and the probability of reaching an 18-21 increases. You can compare the numbers here:

http://www.blackjackinfo.com/bjtourn-dealercharts.php

-Sonny-
 
#4
When playing a H17 game avoiding negative counts becomes much more important. That's where all the damage is done. When you have a huge count, the difference between an H17 and S17 game is negligible, due to the extra time the dealer will end up busting a soft 17. That's why Basic Strategy calls for more doubling in a H17 game.
 

Sucker

Well-Known Member
#5
In an 8-deck shoe, if the dealer hits soft 17 he will bust about 21.2% of the time. Obviously this is a much higher bust rate than if he stands on soft 17, because THEN his bust rate is exactly ZERO.

Here are the figures for when the dealer hits soft 17:

Dealer makes:

17 --------- 34.2%
18 --------- 11.0%
19 --------- 11.2%
20 --------- 11.2%
21 --------- 11.2%
Bust ------- 21.2%

In a nutshell, he's going to improve his hand 44.6% of the time, stay the same about 34.2% of the time, and he'll hurt his hand only 21.2% of the time; so obviously hitting is a huge advantage for the house, and will MORE than make up for the higher bust rate.
 

assume_R

Well-Known Member
#6
Thanks for the responses.

Automatic Monkey said:
When playing a H17 game avoiding negative counts becomes much more important. That's where all the damage is done. When you have a huge count, the difference between an H17 and S17 game is negligible, due to the extra time the dealer will end up busting a soft 17. That's why Basic Strategy calls for more doubling in a H17 game.
Would that mean that if you wonging out at -2, let's say, H17 is not much different than S17 games?
 

tribute

Well-Known Member
#8
After checking the difference between H17 and S17, it appears the house advantage jumps 50% on H17 games for 6-deck, and it doubles for 2D. Gives me all the more reason to find and play the best games.
 
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bigplayer

Well-Known Member
#9
h17/s17 comparisons

The sims I've seen seem to indicate that the 0.2% increase in house edge due to the h17 rules seems diminish slightly at higher counts and seems to increase somewhat at deep negative counts. Regardless, the mere fact that you are giving the house an extra 0.2% head start means that you'll need to be a bit more aggressive on your wonging or use a bigger spread, more conservative in off the top and 0 true-count bets, and more careful about game selection.

It does NOT mean that wonging out at -2 means no difference in the h17 vs s17. h17 is worth about 1/2 a deck in penetration for comparative purposes....although rules become less important than penetration in deeper pen games just as good rules become more important in badly cut games.
 
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tribute

Well-Known Member
#10
bigplayer said:
The sims I've seen seem to indicate that the 0.2% increase in house edge due to the h17 rules seems to at higher counts and seems to increase somewhat at deep negative counts. .
The Basic Strategy Engine on this website points to a much higher increase than 0.2%, in house edge, for H17! (2/10 of 1% is not much increase at all)
 

bigplayer

Well-Known Member
#12
h17

tribute said:
The Basic Strategy Engine on this website points to a much higher increase than 0.2%, in house edge, for H17! (2/10 of 1% is not much increase at all)
I don't know what you're looking at. The Basic strategy engine you mention here has the edge for 6 deck h17 at -0.66% and for s17 at -0.44%. That's 0.22% difference. CBJN has the base six deck game at 0.26% for s17 strip rules and 0.46% for h17 strip rules (difference of 0.2%)
 

21gunsalute

Well-Known Member
#13
Well all the casinos in this area are H17, and while not really desirable I must say that it seems the multitudes here over-react to these games. On many nights you never even see it come into play. One factor that seems to be overlooked here is that it often comes into play when the dealer has a 6 showing and you're sitting on a stiff hand. When she turns over that Ace you're glad she has to hit again.
 

tribute

Well-Known Member
#14
bigplayer said:
I don't know what you're looking at. The Basic strategy engine you mention here has the edge for 6 deck h17 at -0.66% and for s17 at -0.44%. That's 0.22% difference. CBJN has the base six deck game at 0.26% for s17 strip rules and 0.46% for h17 strip rules (difference of 0.2%)
Yes, bigplayer! And that 0.22 % difference you mention is exactly 50% MORE than the percentage for S17! (Take your calculator and add 50% to 0.44 and you get 0.66.)

S17 house advantage: 0.44
H17 house advantage: 0.66
Difference in advantage: 0.22 (which is 50% more )
 
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21gunsalute

Well-Known Member
#15
tribute said:
Yes, bigplayer! And that 0.22 % difference you mention is exactly 50% MORE than the percentage for S17! (Take your calculator and add 50% to 0.44 and you get 0.66.)

S17 house advantage: 0.44
H17 house advantage: 0.66
Difference in advantage: 0.22 (which is 50% more )
You're using the wrong base. The house advantage begins at zero, not at .44. The house advantage is 1/3 higher for H17 (.66) than it is for S17 (.44) (1-.44/.66). And that's 1/3 of a rather tiny advantage to begin with.
 

Blue Efficacy

Well-Known Member
#16
21gunsalute said:
Well all the casinos in this area are H17, and while not really desirable I must say that it seems the multitudes here over-react to these games. On many nights you never even see it come into play. One factor that seems to be overlooked here is that it often comes into play when the dealer has a 6 showing and you're sitting on a stiff hand. When she turns over that Ace you're glad she has to hit again.
I agree. But the house's edge by hitting gets much more powerful the fewer tens are left in the deck. If you have a large amount of excess 8's and 9's, I am sure it is possible H17 can become profitable for the player.
 

21gunsalute

Well-Known Member
#17
Blue Efficacy said:
I agree. But the house's edge by hitting gets much more powerful the fewer tens are left in the deck. If you have a large amount of excess 8's and 9's, I am sure it is possible H17 can become profitable for the player.
But with fewer 10s left you'll be making minimum bets. I agree it works in the favor of the house, but it's not like it's such an unfavorable rule it should be avoided at all costs. I'd rather play S17 but there aren't any such games around here. H17 will bite you once in a great while, but when the count is high it's unlikely to bite you. Like I said, many nights you never even see the dealer with a soft 17 and when the dealer does have soft 17 and hits most of the time it will have no effect on winning or losing the hand.
 

tribute

Well-Known Member
#18
21gunsalute said:
You're using the wrong base. The house advantage begins at zero, not at .44. The house advantage is 1/3 higher for H17 (.66) than it is for S17 (.44) (1-.44/.66). And that's 1/3 of a rather tiny advantage to begin with.
OK. I will try this again.

House advantage begins: 0.00 %
House advantage for S17: 0.44 %
House advantage for H17: 0.66 %

Based on what I learned in skool, 0.66 is 50% higher than 0.44, not 1/3 or 33% higher. (1/3 of 0.44 would only be 0.1466 more.)


So, according to my understanding, the house advantage for H17 is 0.22 more than the house advantage for S17, or 50% more, not 1/3 more.

There is another way of stating this:
Beginning with the 0.66 % house advantage for H17, S17 house advantage is 1/3 LESS than H17 house advantage. (0.44 is 1/3 less than 0.66) (This being YOUR point, 21gunsalute)
 
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SleightOfHand

Well-Known Member
#19
tribute said:
OK. I will try this again.

House advantage begins: 0.00 %
House advantage for S17: 0.44 %
House advantage for H17: 0.66 %

Based on what I learned in skool, 0.66 is 50% higher than 0.44, not 1/3 or 33% higher. (1/3 of 0.44 would only be 0.1466 more.)

So, according to my understanding, the house advantage for H17 is 0.22 more than the house advantage for S17, or 50% more, not 1/3 more.
Why are we arguing the percent increase of the HE going from S17 to H17? This is not a very relevant statistic to consider. How about a game with a .01% HE and a .05% HE? Now its a 500% increase! Does this mean the game is bad? No. All that matters is that there is a .22% OTT increase in HE that must be overcome in order to obtain an advantage for the player.
 

21gunsalute

Well-Known Member
#20
tribute said:
OK. I will try this again.

House advantage begins: 0.00 %
House advantage for S17: 0.44 %
House advantage for H17: 0.66 %

Based on what I learned in skool, 0.66 is 50% higher than 0.44, not 1/3 or 33% higher. (1/3 of 0.44 would only be 0.1466 more.)

So, according to my understanding, the house advantage for H17 is 0.22 more than the house advantage for S17, or 50% more, not 1/3 more.
Okay let's put the shoe on the other foot. If you're playing H17 and want to switch to S17 how much advantage do you gain?


House advantage for H17: 0.66 %
House advantage for S17: 0.44 %
An increase of .22%
.22%/.66%=.33% or 1/3
Any questions? ;)
 
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