Bitcoin Forum

Economy => Marketplace => Topic started by: randomguy7 on February 25, 2011, 12:00:29 PM



Title: Experiences about doubletrouble.bitcoinbet.com?
Post by: randomguy7 on February 25, 2011, 12:00:29 PM
Has someone experience with doubletrouble.bitcoinbet.com?
I played 9 games, won the first and then lost 8 times in a row.
The propability for losing 8 times in a row is 0,51^8 = about 0,46%. This brings me to the question if I'm just really really unlucky or if it's a scam.

Maybe some people who gambled there can report if they also were that unlucky or if their luck followed the statistics better.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: genjix on February 25, 2011, 12:17:50 PM
The chance of losing 8 or more out of 9 games is:

9N8 = from 9 choose 8 = 9

9*(0.5)^9 + (0.5)^9 = 10 * 0.5^9 = 2%

In other words if 50 people played 9 games of double trouble then we expect 1 person to lose 8 or more games.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: Prze_koles on February 25, 2011, 01:21:50 PM
Well, I've lost all money there, not a big sum, but I have now 0 BTC at all  :'(  I don't know if it's a scam or not, I think it's legit. But I will not use any gambling services anymore.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: Mahkul on February 25, 2011, 01:33:12 PM
Hard to tell, I won 5 times in a row; but then again, I lost 5 times in a row as well. ;)

The overall balance is that I have lost much more than I have won.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: randomguy7 on February 25, 2011, 03:58:57 PM
BCEmporium, I think you're right with your theory about how it works. What's supporting the theory is that there's no maximum amount to bet. With a real propability of 49% on each game, someone could simply bet 2^i coins with i=1, increasing i by one after every lost game, until a game is won, thereby getting the lost coins back + 1 coin. Then repeat.

Is anybody interested in a double or trouble like game which delivers proof about every games result? I mean in a way that everybody can recalculate the game results and be sure there was no cheating in any way.
Maybe I setup one if there's enough interest, but there would be a fixed amount to bet on (maybe 1 coin) but with the guarantee to get paid if you win.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: Mahkul on February 25, 2011, 04:24:20 PM
The same guy (MoneyTree) is running Jackpot Dice.

http://bitcointalk.org/index.php?topic=3031.40 (http://bitcointalk.org/index.php?topic=3031.40) I think there was some suspicion that something wasn't right there.

The best solution to that is to publish the hash of the result before the money is bet (just like probiwon does). Well, I guess, this only proves that the result doesn't depend on the amount of BTC bet, but still you have no way of checking how "random" the results are.

BCEmporium is right; I confirmed that with a friend who co-runs a casino and that's more or less the way it is. They always have to win at the end of the day; simple as that.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: ColdHardMetal on February 25, 2011, 04:58:10 PM
BCEmporium, I think you're right with your theory about how it works. What's supporting the theory is that there's no maximum amount to bet. With a real propability of 49% on each game, someone could simply bet 2^i coins with i=1, increasing i by one after every lost game, until a game is won, thereby getting the lost coins back + 1 coin. Then repeat.

That's called a Martingale strategy and it really only works if you have an unlimited amount of money so you can ride out the potential variance.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: AmpEater on February 25, 2011, 05:23:15 PM
I played 4 times and lost every single one.  I wanted to win one just to prove to myself it wasn't just a scam....but then realized that was making me fall for it even more and cut my losses.  I'm glad at least somebody has reported winning


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: randomguy7 on February 25, 2011, 05:32:22 PM
Mahkul: The randomnes of the result could be easily proven if the servers hash is added to some random user input and hashed again. The user already knows the hash of the servers hash when picking its random value, thereby the server can't change his hash and the client doesn't know the servers hash, thereby nobody can't manipulate the end result.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: FreeMoney on February 25, 2011, 05:41:14 PM
It is completely possible to prove that an online casino is running fairly. I don't think bitcoinbet has any interest in doing that though. I have no proof, but I think it was redirecting 6s to 1s on Jackpot Dice. I think after he realized how shady that was he cleaned it up, but dropped the payout to 4x instead of 6x.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: Cusipzzz on February 25, 2011, 09:38:14 PM
The easiest solution is to bet on events where the games AND results are completely public, not some alleged dice roll.

See my sig for more details, lol.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: fornit on February 25, 2011, 11:19:29 PM
betting on random numbers is also easy to realize in a fair and transparent way. since the house still wins 2% per bet, its also still profitable. you only have to limit the bet size and keep the bank stocked to compensate for variance. usually its more profitable to do it that way, because long-term people only play where winning is at least possible, though not likely.


Title: Re: Experiences about doubletrouble.bitcoinbet.com?
Post by: bitcoinex on May 05, 2011, 11:06:03 PM
https://www.bitcoin.org/smf/index.php?topic=3031.msg42895#msg42895