Topic: Just-Dice.com : Invest in 1% House Edge Dice Game - page 209. (Read 435353 times)

Apparently dooglus derived 1% of the bankroll as the maximum bet by trial and error but as it turns out it's been mathematically proved that this is the most efficient maximum bet to optimally grow the bankroll. The proof is called the Kelly Criterion and investors have known about it for years:

http://www.investopedia.com/articles/trading/04/091504.asp

Kelly % = W – [(1 – W) / R]

Where:
W = Winning probability
R = Win/loss ratio

W = 0.505 (bank's edge)
R = 1:1 (profit and loss are both equal for a 2x bet)

Kelly % = 0.505 - [(1 - 0.505) / 1]

= 0.505 - 0.495 = 0.01, or 1% of the bankroll.

Note that a full Kelly Criterion doesn't try to minimize volatility; rather it maximizes growth in the long term.

If you are a short-term investor J-D may not be the right investment for you.

I agree, as long as we keep the tinfoil hats off (celeste has a special edge/cheat), then this is normal variance due to an abnormally large bankroll.  However, it is normal variance which can scare off investors and if celeste does stop playing or continue staying lucky, can dig J-D investors in a hole too deep to earn our way out from in a sane amount of time.  I just know that something needs to be changed - we do not need to have so much larger a max profit per bet than our competitors.  We not even in the same universe with them - they are 3 to 5 BTC and we are 270 BTC?

If J-D is running the game properly, *every* bet is +EV for the bank and -EV for the player.

Under such circumstances there is no such thing as a winning system for the player. The only way a player can be ahead is due to variance. If the player keeps playing, variance will ebb away and their balance will tend to match their expectation, i.e. -1% of the total amount wagered.

I'm sure if there is a flaw in the game dooglus will find it. If there is no flaw in the game, investors just need to be patient and not panic every time a whale gives the bank a beating. Or, if it's too stressful for you, seriously think about cashing out.

The problem with such players is not their "system," it's time.
If she plays until she gets a little profit, then she'll get busted eventually.  But since
she has a big bankroll, getting her busted takes time.
In other words, the consistency of winning
is illusory; it's like the consitency of winning on the 98% roll.

The profit would vary much smoother if there were many players like celeste. With only one,
all the investors can do is to wait.  Either she stops playing, or she gets busted.

So I did some research to see what our competition does differently.  I think Dooglas has gone too far trying to make just-dice have the most liberal parameters to the point it is not sustainable for investors.

Primedice: 1% edge, Max payout 3 BTC (at 2X, goes up to 5 BTC at longer odds such as 10X)
Coinroll: 1% edge, Max payout 5 BTC (per the faq)
Satoshidice: 1.9% edge, Max payout variable (someone told me it increases the longer the bet odds similar to primedice)
Just-Dice: 1% Edge, Max Payout 1% Bank Roll (currently Max Payout just under 300 BTC)

Seems with normal betting patterns, investors make a small profit over time.  One day 2 BTC up the next 1 BTC down.  However, when a whale comes in with a huge balance of his own (such as celeste ID # 31791) then with a consistent system, seems to be able to eventually win most of the time.  Celeste is smart, he walks away once he is ahead enough.  Today came from 800 BTC down to 300 BTC up and then stopped betting.  His bankroll seems to be close to half the size of the invested bank roll.  

If celeste (who used a couple other aliases) just won occasionally, I would chalk it to normal variance.  However, it really is consistent and the small profits of 1 BTC/day on average is wiped away in a short time when this whale visits us.  I do not blame the whale, I do not think they are cheating as in having the server seed (though if you watch him play, he does seem to rage bet at the right times always).  I think our parameters are not well chosen and investors will often lose to a whale.  

Looking at our competitors, I would say raising the edge would be a mistake since primedice offers a similar interface and edge matters most to gamblers.  However, with the other competitors who have a 1% edge offering a max profit per bet of 3 BTC and 5 BTC respectively, our max profit per bet of currently 270 BTC is a couple of orders of magnitude larger.  

My personal preference is to keep the 1% edge and bring the max profit down a lot but still keep it significantly bigger than our competitors.  If we broughtt it down to 0.2 of the bank roll, that would still be 54 BTC per roll - over 10 Xs our nearest competitor.  We will be more consistently profitable and the whales will keep playing at J-D since we will continue to be much better than our competitors.  As it stands right now, Just-Dice is great for players (especially ones with huge balances) but not a good deal for its investors.  I think with some small tweaks it can continue to be the most popular dice game and be a good investment as well.

I am not looking for +/- 10% changes in my investment on a daily basis, that level of volatility is no different than just gambling ourselves.  I think I and most other larger investors would be fine with +/- 1% changes.  I really hope some changes are made, since the investor pool will eventually start shrinking if these losses keep adding up.  

I'd be interested to see an analysis of the distribution of bet sizes on JD. e.g., how many bets are 0.1-1% of the bankroll, 0.01-0.1%, etc. I suspect that the number of 'large' bets is still too small for variance to be eliminated as the cause of the bank's losses.

Down another 250 BTC for the site.  Seems we lose everytime the whale plays.  He is a smart whale, he walks away once he gets ahead enough.  Seems that with 1% max profit with a 1% edge, a whale with a consistent system and large enough bank roll consistently wins. Everyone compares us to SD, but they have a 1.9% edge so it not a comparison at all.  I wonder if players would tolerate a higher edge say 1.5% (still lower than SD but more than primecoin) but we keep the high max profit per bet? I don't know but ti seems like something needs to be tweaked.  Investors will start divesting at some point soon if it to be consistent losses.

Aaaand.  It's gone.  damn.

Except the millionaire just returned to breakeven or better!

And JUST LIKE THAT, the site (and investors) has already recovered the entire freeroll 'losses'.  For the moment.

Thank you celeste for continuing to play and have faith in your 'system'.

Max bet as percentage of bankroll (see upper right legend), assuming whale ONLY does max bets on 50/50 with 1% house edge.  Max bet adjusts after each result.

how was 'max bet' determined in this simulation? is it a percentage of bankroll or a specific number? and did the wins and losses affect the max bet as the simulation went on?

I'd guess you need in the order of 100s of millions of bets before statistics really takes hold. And really it's only the large bets that make the difference, so 100s of millions of those. All the little 0.0000001 stuff is pretty meaningless.

Luck is calculated as (# bets won) / (expected # of bets won) x 100%.

The expected # of bets won can be calculated by simply summing up the win-chance for every bet.

almost 29 million bets. But I'm not sure how the "luck" % is calculated. Does it takes into account that bets does not have 50%/50%?

Number of bets would be more relevant. Seeing those broken down by bet size would also be good.

324k bitcoins wagered is not enough?
We will see where we are, at 500k

Give it time and let the math do its thing.

- 1 200 btc.
Some early investors got lucky and won some coins? But what about the others?