Page 1 of 2 12 LastLast
Results 1 to 13 of 16

Thread: ROR and Bankroll: A General Discussion Thread

  1. #1
    Senior Member Aslan's Avatar
    Join Date
    Dec 2011
    Location
    Bethesda, MD / Las Vegas NV
    Posts
    2,808


    Did you find this post helpful? Yes | No

    ROR and Bankroll: A General Discussion Thread

    Quote Originally Posted by ohbehave
    Plain and simple... We like talking about blackjack and AP related topics. Thats why we're here. So someone makes a post and then we talk about all the stuff we've already talked about 1000 times... because we like to.
    Quote Originally Posted by Tthree
    Here is the actual definition of your BR:

    Your BR is how much of your net wealth you are willing to lose before abandoning the idea of AP blackjack.
    Whatever your bankroll, which is a set amount, whether it's your entire wealth or a smaller amount, say $10,000, my idea of ROR is the chance of losing that amount before doubling that amount. If you double it, theoretically, you now have two bankrolls. I'm assuming of course that you did not change your bankroll amount or your plan for game min and max bet anywhere along the line, which as a practical matter probably does not often happen. But for me, its more of a conceptual thing that helps one get in an acceptable ballpark for actual play.

    Aslan 11/1/90 - 6/15/10 Stormy 1/22/95 - 8/23/10... “Life’s most urgent question is: what are you doing for others?” — Martin Luther King, Jr.

  2. #2
    Senior Member
    Join Date
    Dec 2011
    Location
    3rd rock from Sol, Milky Way Galaxy
    Posts
    14,158


    Did you find this post helpful? Yes | No
    Quote Originally Posted by Aslan View Post
    Whatever your bankroll, which is a set amount, whether it's your entire wealth or a smaller amount, say $10,000, my idea of ROR is the chance of losing that amount before doubling that amount.
    I think you just gave Don an aneurysm.

  3. #3
    Senior Member Aslan's Avatar
    Join Date
    Dec 2011
    Location
    Bethesda, MD / Las Vegas NV
    Posts
    2,808


    Did you find this post helpful? Yes | No
    Quote Originally Posted by Tthree View Post
    I think you just gave Don an aneurysm.
    I think I got it from the authors of Knockout, but I think I threw that book away. But here in Exhibit CAA: Beyond Counting, it states:

    Risk of Ruin. The probability of losing a specified amount of money before reaching a a target. By convention, the probability of losing a bankroll before doubling it. page 625, 94 Appendix H, Glossary.

    I have no desire to upset Don. I appreciate his posting on this Forum. I'm not at all in his league blackjack knowledge-wise. Besides, I live in a glass house.

    Aslan 11/1/90 - 6/15/10 Stormy 1/22/95 - 8/23/10... “Life’s most urgent question is: what are you doing for others?” — Martin Luther King, Jr.

  4. #4
    Senior Member Aslan's Avatar
    Join Date
    Dec 2011
    Location
    Bethesda, MD / Las Vegas NV
    Posts
    2,808


    Did you find this post helpful? Yes | No
    Quote Originally Posted by moses View Post
    Blackjack is not a game for the poor or faint of heart. Not to seem harsh, but there is just too many things that go on beyond ones control. Worrying about downturns is like an official worrying about mad coaches. It will happen. It's more important not to be surprised by it and know how to deal with it. If getting 86ed is not of far more concern than R of R then your game needs work.
    Who's worrying? Not planning adequately is a different matter. ROR helps one determine a sufficient bankroll size. If you live in an area that experiences severe windstorms, I'd take the wise pig's advice and build a house of brick. IMHO the wise player takes as much into his control as possible. Playing with insufficient bankroll is a recipe for disaster. But don't take my word for it. YMMV. They say it's better to be lucky than good, whatever that means-- it's one of those after-the-fact measures.

    Aslan 11/1/90 - 6/15/10 Stormy 1/22/95 - 8/23/10... “Life’s most urgent question is: what are you doing for others?” — Martin Luther King, Jr.

  5. #5


    Did you find this post helpful? Yes | No
    Even though I was anticipating Don's definition of RoR (the chance of going bust before you win it everything in the world, though not how I phrased it) I've always found that definition a bit hard to grasp. Assuming a fixed betting pattern (non-percentage of your bankroll), I understand that part of the time, someone will run up their bankroll to the point where going bust becomes extremely small. However, even if you x1000 you bankroll, you would still have some RoR (even if turns out to be in the +3SD range). It just seems that given an infinite amount of play that all bankrolls would go bust (though a number of them will take forever to get there). Is there some part of Don's definition I'm missing or misunderstanding?

    Note: I was a bit confused about whether it was appropriate to post this to the original thread or here since the question does seem like a natural extension to the answer I received. Oh well, I'll play it safe :P

  6. #6
    Senior Member
    Join Date
    Dec 2011
    Location
    3rd rock from Sol, Milky Way Galaxy
    Posts
    14,158


    Did you find this post helpful? Yes | No
    Well Don was a pioneer in a lot of the stats and terms we use today. We used DI which was an exponential scale until Don invented SCORE which has a linear scale. I don't want to say he invented terms when I am not sure but he at least took terms to a new level of understanding. I think he made a concerted effort to standardize terms so everyone is on the same page in the conversation. Unless otherwise specified RoR is the term Don defined. Unless otherwise specified SCORE means the standardized BR, spread, RoR etc. I can understand Don's frustration as, what I assume was a goal of his in what is among the top few must have blackjack books (BJA3 is the top blackjack book in my opinion) to have, people misuse the terms he tried so hard to standardize or defined himself without any qualification.

    It just makes conversation much easier and communication less confusing if everyone uses standard terms and specifies when they are using a hybrid of the term like RoR meaning doubling your BR before going bust. The reality is RoR changes constantly as you win and lose money so the idea of adding a goal seems silly unless you resize your ramp at that goal. Then RoR would be best defined as the chances of hitting your resize to a bigger ramp goal before hitting your resize to a smaller ramp goal. As you win money but are still short of the goal your risk of downsizing your ramp (a more accurate term rather than muddying the term RoR as it was originally defined) goes down and as you lose money it goes up. I think that was what was in mind when the double your BR goal RoR hybrid is used.
    Last edited by Three; 02-23-2015 at 01:31 PM.

  7. #7


    Did you find this post helpful? Yes | No
    Maybe this should be on another thread but as Ohbehave wrote, we like to talk about BJ so here goes.....

    I am curious to know how many AP's began their AP Career's with a BR large enough to enjoy a low R.O.R? I began my AP play with an extremely high R.O.R. I now play in a much safer zone, as I have built a BR that provides a low R.O.R..by simulation standards.

  8. #8
    Senior Member
    Join Date
    Jan 2012
    Location
    Midwest
    Posts
    1,055


    Did you find this post helpful? Yes | No
    I, long ago accepted the fact that Don is light years ahead of me in the math of this game (and grammatical expertise to a lesser degree). It was at about the same time that I realized that I was somewhat ahead of him in diplomacy/tact skills.
    I'm guessing that he happily accepts that reality.

    muffdiver

  9. #9


    Did you find this post helpful? Yes | No
    Nice answer. Let me explain just a little more. ROR is an absolute term. It means the risk (chance) that you will lose all your money devoted to playing. PERIOD!! It is we who decide to play around with that "pure" definition, by introducing goals. In the ROR chapter of BJA3, you will see that I furnish highly sophisticated double-barrier formulas, adapted from finance and options trading, that permit you to enunciate not only a ROR, but also the probability of reaching a goal before going bankrupt. And that goal can be anything! There is absolutely nothing special about doubling. NOTHING! So, why make that part of any definition? The answer is: you shouldn't. Why doubling? Why not winning 150% or tripling?

    What happens when you double? Do you turn into a pumpkin? What changes? Again, the answer is ... nothing! But wait. You say, if I double my bank, I increase my stakes. Well, WHOA! Now, you've changed everything! And surely your ROR isn't what you think it is if you accept MY definition. Everyone should really go to Norm's online calculators of my many formulas and play with them, as I have done, for hours upon hours, to get a good sense and feel of this topic. One of the reasons that doubling appeals to people is something that I discuss in my chapter. "If they don't get you early, they are unlikely to ever get you at all," is, more or less, the way I described it. So, if you don't change your stakes, and you double your bank, the risk of losing it ALL bank from that point is very small indeed. So small, in fact, that the probabilities look very similar to the "pure" ROR numbers without any upper-bound goal or constraint.

    I hope this clears up a few points.

    Don

  10. #10


    Did you find this post helpful? Yes | No
    Hi, Don!

    Yes, thanks, that is very helpful. This discussion reminds me of N0 where the definition most people use (and Dr. Brett Harris used) is the amount of advantage play needed to overcome 1SD of negative results. But, 1SD is just a convenient number to use for various reasons, somewhat like DOUBLING the bank is often used with RoR. With 1SD, you get about 84% probability of being even or ahead and most people seem content with that, probably because it meets your idea of "If they don't get you by then, you're probably ok."

    With N0, however, you can use ANY measure you want. You might be more comfortable with N0 at 2 SD. It's just a calculation that tells you the probability of being even or ahead after X rounds of advantage play. Similarly, with RoR, you could use a doubling or a tripling or whatever bankroll increase makes you feel comfortable.

    I can see a small problem where people use the terms differently without specifying the details of the calculation.

    Best,
    SiMi

  11. #11


    Did you find this post helpful? Yes | No
    Quote Originally Posted by DSchles View Post
    "If they don't get you early, they are unlikely to ever get you at all," is, more or less, the way I described it. So, if you don't change your stakes, and you double your bank, the risk of losing it ALL bank from that point is very small indeed. So small, in fact, that the probabilities look very similar to the "pure" ROR numbers without any upper-bound goal or constraint.

    I hope this clears up a few points.

    Don
    Yep, this is pretty much what I was hoping for. Especially the statement about the probability of losing our doubled bank being similar to "pure" ROR numbers. Thanks for the great explanation!

  12. #12


    Did you find this post helpful? Yes | No
    Yes, agree with everything you've written.

    Don

  13. #13
    Senior Member Aslan's Avatar
    Join Date
    Dec 2011
    Location
    Bethesda, MD / Las Vegas NV
    Posts
    2,808


    Did you find this post helpful? Yes | No
    Quote Originally Posted by DSchles View Post
    Nice answer. Let me explain just a little more. ROR is an absolute term. It means the risk (chance) that you will lose all your money devoted to playing. PERIOD!! It is we who decide to play around with that "pure" definition, by introducing goals. In the ROR chapter of BJA3, you will see that I furnish highly sophisticated double-barrier formulas, adapted from finance and options trading, that permit you to enunciate not only a ROR, but also the probability of reaching a goal before going bankrupt. And that goal can be anything! There is absolutely nothing special about doubling. NOTHING! So, why make that part of any definition? The answer is: you shouldn't. Why doubling? Why not winning 150% or tripling?

    What happens when you double? Do you turn into a pumpkin? What changes? Again, the answer is ... nothing! But wait. You say, if I double my bank, I increase my stakes. Well, WHOA! Now, you've changed everything! And surely your ROR isn't what you think it is if you accept MY definition. Everyone should really go to Norm's online calculators of my many formulas and play with them, as I have done, for hours upon hours, to get a good sense and feel of this topic. One of the reasons that doubling appeals to people is something that I discuss in my chapter. "If they don't get you early, they are unlikely to ever get you at all," is, more or less, the way I described it. So, if you don't change your stakes, and you double your bank, the risk of losing it ALL bank from that point is very small indeed. So small, in fact, that the probabilities look very similar to the "pure" ROR numbers without any upper-bound goal or constraint.

    I hope this clears up a few points.

    Don
    Don, I am not trying to try you patience or to be argumentative with someone I believe has forgotten more about blackjack than I have learned. I do understand what you are saying, but I do give some weight to what other blackjack authors say as well. I believe the doubling your bankroll concept works well as a practical matter with a person who wants to play at a certain level and never more. For example, a person dedicates $25,000 to be his bankroll. He has decided if he loses it he will quit AP play. He plays a $25 min game, average rules and good pen, with a $250 max bet for shoe games and a $125 max for DD games. When he achieves doubling his bankroll he does not turn into a pumpkin, but according to his design he has achieved a doubled bankroll. This man does not now move to a $50 min game because he now has a $50,000 bankroll, but continues on with the same $25 min game, his ROR now dramatically reduced. I am not at all disputing your more pure look at the mathematics. Yes, it is we who have played with the pure mathematical concept, but I think to good end. Personally, I have no desire to ever move to a $50 or more game. Too much heat in IMHO. In short, I find it easier to wrap my mind around the doubled bankroll concept. This is not to say I disagree with anything you have said.

    Aslan 11/1/90 - 6/15/10 Stormy 1/22/95 - 8/23/10... “Life’s most urgent question is: what are you doing for others?” — Martin Luther King, Jr.

Page 1 of 2 12 LastLast

Similar Threads

  1. Discussion battle
    By KJ in forum General Blackjack Forum
    Replies: 18
    Last Post: 07-15-2014, 05:50 PM
  2. Another taking a hail mary shot on a small bankroll thread, please weigh in
    By mcallister3200 in forum General Blackjack Forum
    Replies: 170
    Last Post: 06-05-2014, 01:19 PM
  3. This discussion needs to take place.
    By falling star in forum General Blackjack Forum
    Replies: 2
    Last Post: 01-27-2013, 06:48 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

About Blackjack: The Forum

BJTF is an advantage player site based on the principles of comity. That is, civil and considerate behavior for the mutual benefit of all involved. The goal of advantage play is the legal extraction of funds from gaming establishments by gaining a mathematic advantage and developing the skills required to use that advantage. To maximize our success, it is important to understand that we are all on the same side. Personal conflicts simply get in the way of our goals.