Splitting 10's against a six

#1
A friend of mine is insisting that splitting 10's against the dealer's 6 is a 50/50 decision. I remembered that that wasn't the BS, but i couldn't explain why. Could someone spell out the logic of the BS in this situation?

(Also, why not to split 9's vs. 7, if possible. thanks)
 
#2
AsparaChief said:
A friend of mine is insisting that splitting 10's against the dealer's 6 is a 50/50 decision. I remembered that that wasn't the BS, but i couldn't explain why. Could someone spell out the logic of the BS in this situation?

(Also, why not to split 9's vs. 7, if possible. thanks)
Why attempt 'logic'? The logic is simply what the computer simulations detirmine.

With 10s against 4-5-6 you will profit whether you split or stand BUT there is more profit in standing. Same goes for 9s v. 7. zg
 

Canceler

Well-Known Member
#3
Now I do feel like an idiot.

I was going to be helpful, and supply some statistics. And I can do that. These numbers are from bjmath.com for 6D, H17, DOA, DAS.

EV for T,T vs. 6
Stand: 0.67659
Split: 0.430478

EV for 9,9 vs. 7
Stand: 0.399576
Split: 0.363783

Now here's the really dumb part: I don't know how to interpret this. For T,T vs. 6, my understanding is that if I stand, I'll win 68 cents per dollar bet. But what about splitting? Can I expect to win 43 cents per dollar bet? Since I'm betting two dollars now, that would be 86 cents, so why not do it? Yet I know this isn't right. So, 43 cents per what?

Anybody feel like explaining this simple concept to this beginner here? :eek:
 

MGP

Well-Known Member
#4
I agree with zengrifter except:

Why attempt 'logic'? The logic is simply what the computer simulations determine.
It's actually combinatorial analysis and not simulation that's determined basic strategies. Simulation isn't as accurate.

For T,T vs. 6, my understanding is that if I stand, I'll win 68 cents per dollar bet. But what about splitting? Can I expect to win 43 cents per dollar bet? Since I'm betting two dollars now, that would be 86 cents, so why not do it? Yet I know this isn't right. So, 43 cents per what?
The convention is the return for the total hand so even though there are 2-4 bets out with splitting, the expected return is 43c net. This is also true for doubling.
 

ScottH

Well-Known Member
#6
MGP said:
I agree with zengrifter except:

It's actually combinatorial analysis and not simulation that's determined basic strategies. Simulation isn't as accurate.
Isn't simulating a billion hands basically like working it out exactly? Simulation is just an estimate, but after so many hands it's pretty much dead on.
 

dacium

Well-Known Member
#7
Its not two lots of 43 cents it, its 43 cents compared to the original bet. So splitting way worse off.

Under my calculator and slightly different rules I got:

For split it was 121.51% win 13.66% and 64.83% loose (total of 200% bets) for EV of 56.677%

For stand it was:
Won: (80.04%)
Push: (10.20%)
Lost: (9.76%)
Bets: 1.000000000000E+000 (100.00%)
EV: 7.028260413409E-001 (70.283%)
2305 Possibilities computed in 0 seconds
 

MGP

Well-Known Member
#8
ScottH said:
Isn't simulating a billion hands basically like working it out exactly? Simulation is just an estimate, but after so many hands it's pretty much dead on.
Not to 16 decimal points ;)
 
#9
MGP said:
Not to 16 decimal points ;)
Bet it's not valid to 16 decimal places though. Do combinatorial analyses consider the card-eating effect of hit/stand decisions on the rest of the shoe? That's got to be worth more than the 16th decimal place.
 

MGP

Well-Known Member
#10
Automatic Monkey said:
Bet it's not valid to 16 decimal places though. Do combinatorial analyses consider the card-eating effect of hit/stand decisions on the rest of the shoe? That's got to be worth more than the 16th decimal place.
Yes they do. The only effect for a BS player that isn't accounted for is the cut-card effect - but they are exact for top of the deck values and for games with a fixed number of rounds - so there :p!

Seriously though, sim is fine, but for basic startegies CA is more accurate and faster.
 
#11
Attempt at logic

AsparaChief said:
A friend of mine is insisting that splitting 10's against the dealer's 6 is a 50/50 decision. I remembered that that wasn't the BS, but i couldn't explain why. Could someone spell out the logic of the BS in this situation?

(Also, why not to split 9's vs. 7, if possible. thanks)
Explain to your friend that the dealer is sometimes going to to make his stiff hands and if you have a 20 hand, you're probably still going to win. If you have two face cards, you actually improve the dealer change of making his his stiff hand, because those two face cards arn't in the deck to help break his hand. If you split, you're giving up your advantage over the dealer and improving his chances of beating you. You split a poor hand to make two good ones, not a good hand to make two poor hands.

When the dealer has a 7, he'll only break 26% of the time. The two 9s in your hand lessen the chance of the dealer getting a 16.
 

dacium

Well-Known Member
#12
People that say 'sims mean nothing' are idiots.

Yes sims don't get you exact values but they do show you variance. Whats the point of considering a certain move that should be made to 3 decimal places of accuracy when in a sim over millions of hands it will float up and down? For example 16 vs 10 hit or stand (and a few others) are so touchy that over ones whole lifetime you are likly to even get more than 1 or 2 units difference.
 

MGP

Well-Known Member
#13
dacium said:
People that say 'sims mean nothing' are idiots.

Yes sims don't get you exact values but they do show you variance. Whats the point of considering a certain move that should be made to 3 decimal places of accuracy when in a sim over millions of hands it will float up and down? For example 16 vs 10 hit or stand (and a few others) are so touchy that over ones whole lifetime you are likly to even get more than 1 or 2 units difference.
I'm not sure if I should take offense at this or not since I'm the one who commented on the decimal places. If you are calling me an idiot than maybe you should actually look at the posts before you make a fool of yourself. The winking smiley clearly indicated I was joking and I didn't say sims mean nothing. I still stand by the fact that for basic strategies sims are less accurate and much slower. Variance for everything except splits is trivial to calculate and even for splits you can get close estimates very quickly, so even if that's what you want ca makes more sense.
 

Cardcounter

Well-Known Member
#14
reason for not splitting 10's!

The reason for not splitting tens against a six is that you have a hand that will usually win against a 6. If you split your tens and win one and lose one that is often a worse result than standing.

The reason why you do not split two 9's vs a 7 is the dealer is more likely to have 17 when the dealer is showing a 7 if you stand you have a winning hand on the average.
 

ihate17

Well-Known Member
#15
Please change your name

Cardcounter said:
The reason for not splitting tens against a six is that you have a hand that will usually win against a 6. If you split your tens and win one and lose one that is often a worse result than standing.

The reason why you do not split two 9's vs a 7 is the dealer is more likely to have 17 when the dealer is showing a 7 if you stand you have a winning hand on the average.
With a name like cardcounter, I am really very surprised by this post. Every system of cardcounting that has value, also has indices for where you will win more money by splitting tens vs 5 or 6 and for splitting 9's vs 7.
You post is accuracte as far as basic strategy is concerned, but you named yourself "Cardcounter"? (Learning to count is a much more accurate name.)

ihate17
 
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