Getting started, RoR, SD etc.

H

hammer1570

New Member
#1
#1
Having real problems trying to get my head around these issues. I am aware of what each means, yet when I try to draw up a rough plan I'm coming out with all sorts.

Going through BJ Attack, it states that SD per hand = 1.1, yet in the RoR tables the min. SD it provides is 1.5, surely if SD is really 1.1 per hand then the table would clearly go down to that number, which leads me to thinking I am doing something wrong.

Also in the tables it suggests that an expectation of 0.005 units per hand possess more RoR than an expectation of 0.05. Real confused.

Any help via PM or through this thread would be greatly appreciated.

If it helps I will be playing the game with standard UK rules, 5000 bankroll.

Thanks.
 
FLASH1296

FLASH1296

Well-Known Member
#2
#2
"Standard U.K. Rules" are not very good. Games like that require an optimal spread,
which, with mediocre penetration, is rather aggressive.
Playing thusly, your R.O.R. increases, because you are getting more
money on the felt and varying your wagers radically and more frequently.

Your ROR increases proportionately to your expectation in cases like this.

The R.O.R. would be inversely proportional in a game with excellent rules
deep penetration; especially if a "play-all" approach is avoided.

Actually, I am uncertain about the accuracy of my last statement.
 
UK-21

UK-21

Well-Known Member
#3
#3
I don't have a fixed bankroll when I play. What I have done is create a spreadsheet that, when the betting ramp, house edge, unit value and number of hands I expect to play are entered will give a fairly good estimate of the maximum I could lose (3 Std Devs below the EV) and I could win (3 Std Devs above the EV) for the session. It isn't perfect and there is always the possibility of a 4+ Std Dev occurance. But what it does do is tell me how much I need to take with me to the house of chance to avoid running out of money early on. Although I don't play too often, I've never yet got close to losing the amount I've taken to play with.

Generally, if you divide your £5K by 600 you get c£8.30, and if you take this as your max unit bet (let's say £8) then the chances of you losing all £5K (assuming you play error free and don't go on tilt) is minimal - less than 2% I read somewhere (although I'm sure others will be able to offer more precise results). Regardless of which book you read, it's recommended that a bankroll should never be less than 400 units, otherwise losing the lot becomes a distinct possibility, not an outside chance.

RoR calcs are quite difficult due to the many variables within the game.
 
Sonny

Sonny

Well-Known Member
#4
#4
hammer1570 said:
Going through BJ Attack, it states that SD per hand = 1.1, yet in the RoR tables the min. SD it provides is 1.5...
Click to expand...
The SD is about 1.1 for a flat-betting BS player. It will be higher for someone who is spreading their bets, like a typical card counter.

hammer1570 said:
Also in the tables it suggests that an expectation of 0.005 units per hand possess more RoR than an expectation of 0.05. Real confused.
Click to expand...
That definitely sounds wrong. Is that for the same bankroll?

-Sonny-
 
K

Kasi

Well-Known Member
#5
#5
hammer1570 said:
Also in the tables it suggests that an expectation of 0.005 units per hand possess more RoR than an expectation of 0.05. Real confused.
Click to expand...
Well, maybe you are looking at the "Bankroll=x units" tables in CH 8.

There, the ROR is lower for an expected win rate for 0.05 units per hand vs 0.005 units per hand at the same SD per hand.

In other words, the table assumes the same number of units, not dollars, in your roll under both circumstances.

And ROR depends on the ratio of win rate vs SD per hand - I doubt if you will ever find a game that will have same SD/unit per hand and have a unit win rate 10X different.

If you turn a couple of pages to the "ROR=X" section, you may be able to see how that changes things as far as units in roll goes to keep risk the same.

Flash forward to CH 10 and the first Table 10.4

Playing all with a 1-8 spread and $10K roll, one's win rate is 0.0029 units per hand and ones SD per hand is 2.85 units. One's unit is $5 and therefore one has a 2000 unit roll and a Kelly ROR.

Same game, with same $10K roll, but back-counting, spreading 1-2, one's win rate is 0.016 units per round, one's SD is only 1.48 units per round, but one's unit is now $75 instead of $5 and therefore one's unit roll with $10K is 133 units. And, here's the thing, one's ROR is the same in both cases.

As an aside, put another way, whether you play with $5 or $500K roll, it won't change your unit sd/hd or your unit EV per hand. It would only change the number of units in your roll and, more units=lower risk in same game.

Does that make sense to you?

The real kicker is one will never know one's EV in units per hand and one's SD in units per hand without running a sim.
 
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