How true count is calculated in blackjack ?

Hello people, my first post here!

I was reading on wizard of odds (and on few others sources) that the True Count is = Running Count / number of decks left (for example if the running count is +9 and the number of remaining decks is 3, then the true count would be 9/3=>+3) right ?

However, I saw on a gambling website wich offer blackjack games that they encourage people to count (using Hi/Low) and they advise that True Count should be: ``Step 2 - The True Count The true count is reached by dividing the count by the number of half-decks remaining.
At the start of a blackjack game there are 4 full decks, hence you would divide by 8. Once 26 cards had been dealt, there would now be just 7 half-decks left.
If the count at this point was 14, then the true count would be 14/7 = 2`` - ARE THEY DUMB or I am blind ? (nope, I have triple checked.. im not blind) Thanks !

PS: Why in the world they would do such an affirmation ? (has anyone any idea ? - because I don`t)

Please confirm me who is wrong, thanks in advance !

Quote: PlayHunter

Hello people, my first post here!

I was reading on wizard of odds (and on few others sources) that the True Count is = Running Count / number of decks left (for example if the running count is +9 and the number of remaining decks is 3, then the true count would be 9/3=>+3) right ?

However, I saw on a gambling website wich offer blackjack games that they encourage people to count (using Hi/Low) and they advise that True Count should be: ``Step 2 - The True Count The true count is reached by dividing the count by the number of half-decks remaining.
At the start of a blackjack game there are 4 full decks, hence you would divide by 8. Once 26 cards had been dealt, there would now be just 7 half-decks left.
If the count at this point was 14, then the true count would be 14/7 = 2`` - ARE THEY DUMB or I am blind ? (nope, I have triple checked.. im not blind) Thanks !

PS: Why in the world they would do such an affirmation ? (has anyone any idea ? - because I don`t)

Please confirm me who is wrong, thanks in advance !

Always divide by the number of whole decks remaining. What I think this site is TRYING to say is that you should be more precise in deck estimation. Instead of rounding to the nearest full deck, round to the nearest half deck, and divide by that. A half-deck resolution will give you a better estimation of the true count than a full-deck resolution. Although I agree that that's true, I personally find dividing by the number of whole decks remaining to work just fine. Half-deck resolution only changes decision making on really close calls, and the closer the call, the less costly it is to make the wrong one. Ever tried to divide by 3.5 in your head?

Quote: kmcd

Ever tried to divide by 3.5 in your head?

Easy: divide by 7 and multiply by 2 :)

Thanks for clearing me. Yes, now I understand what they wanted to say. And I consider it a very good point! But the only thing was wrong with them was that they did not pointed out that clearly at all, lol. Thanks anyway, your exlanation is very clar and I can easly understand it. Cheers !

Quote: weaselman

Easy: divide by 7 and multiply by 2 :)

Yes, because sevenths are so easy to calculate. That said it's not actually too hard to memorize sevenths, just a pain in the ass to think of them on the spot:


1/7 = .142857 (repeating)

you can achieve any other 1/7 fraction by moving the decimal place. (e.g. if you move it two spots to the right you have 2/7, just 1 spot would give you 3/7....) But somehow those values are just not something I'm willing to work with in the context of a live blackjack game. That's actually why I specifically mentioned dividing by 3.5. This is probably the most difficult denominator of a half-deck resolution six-deck true count conversion. Not only must you divide by 7, but you must also multiply it by 2. Must be fun to do that for your indexes while also keeping the running on everyone else's hand. With a resolution of full deck not many of your betting decisions will change, but you'll always be dividing by an easy denominator.

I also know certain key points. For instance if the running is > 9 I'll always raise my bet, even on the second hand of a shoe, because it is impossible for the true to be less than 1.5 in that condition. Towards the end of the shoe, I know that > 3 is a raised bet as well as penetration of a six-deck shoe is never worse than 67%. Or if it is I wouldn't be playing in the first place.

Because dealers tend to not allow much time for someone to make an insurance decision (especially on a shitty hand), I don't calculate a count for it. I just know that when I have a 5 unit bet out (my standard +4 or +5 TC bet) I will take it. at +3 it's profitable, but the small error in the middle of the +3's is not incredibly costly as although insurance is profitable, it's not VERY MUCH so.

Quote: kmcd

Yes, because sevenths are so easy to calculate. That said it's not actually too hard to memorize sevenths, just a pain in the ass to think of them on the spot:


1/7 = .142857 (repeating)

I don't know what you could possibly need this much resolution for. If 3.5 decks are remaining, all you need to be able to figure out is that if the running count is 7, then TC is 2, if it is 10, TC is about 3, 14 is 4 etc. To do that, you just need to to divide 14, 21, 28 etc. by 7. Not hard, is it?

" although insurance is profitable, it's not VERY MUCH so. "

You need to try another game. Insurance is responsible for 30% of an AP's profit. Of course I might be wrong, but if that's true, so are the Wiz and some nobody named Stanford Wong!