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Topic
Board Beginners & Help
Re: kingco.in <- stay away(?)
by
coolidgecoin
on 07/05/2013, 03:05:11 UTC
Owner here. Sorry for the trouble Kingcoin gave you. I am traveling at the moment but will address this on the next two days when I'm home. All games are logged, so worry not--we will get to the bottom of this. Let's sort this out over email and you can post your experience when we have resolved the issue.
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 28/11/2012, 23:02:32 UTC
Updates to Kingcoin

November 28, 2012
A minimum bet amount of 0.01 is now required (either BTC or points).
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 28/11/2012, 23:00:42 UTC
Hello Sanjay,

This game is quite addicting. I have an uncanny urge to look at advice animals though...

One very minor thing I noticed:

When playing with actual bitcoins, if there is no immediate combo available (i.e. one spin remaining with 2 spins blue, 1 green, and 1 red) the text overlay on the wheel says "Keep spinning! Or sign up and play for real bitcoin!". It doesn't affect gameplay, but I definitely hesitated the first time I saw it.

Correction: I just replicated the message after 2 spins.

Thanks for the feedback, tyrannis! I'll look into the messaging issue you mention.

Sanjay
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 26/11/2012, 20:09:19 UTC
Even though you cannot know that the games shown were actually played by other players, each individual player can be sure that his or her own games are correctly shown on that page. As such, if any player notices that his or her own games are not correctly shown, that player can raise a red flag and alert the community.

I think the point is that you could easily add in a bunch of imaginary winning games to make it look like on average the site is performing as advertised.  Nobody could prove that the added games weren't real.

It's still interesting to see the list of recent games.  I just don't think it really proves anything.  (Not like your provably fair hashes do).

Ah, I see. Yep, you're right, I could be making up games in the log to make it look like people are winning (I'm not!).

Sanjay
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 26/11/2012, 08:08:40 UTC
  • The expected value of Kingcoin has increased to be competitive with other games. It is now approximately 0.984.

That's excellent!

  • Each game is logged in the database with more details (in case I have to process refunds)

Is that no longer publicly visible? (at least the last 100 plays like was available previously)?

I suppose that isn't really useful as I cannot verify that the plays that weren't mine were actually for other players, so it provides really no value for verification but it was interesting to see someone else's string of luck giving me hope that maybe, just maybe, the next string like that will be mine. :-)


[Edit: History is still there.  I'm not sure how I didn't see it before.
 - http://kingco.in/history.php ]

Stephen, pardon me, I'm going to comment on your redacted (struck-out) text. Smiley I believe the 100-game history is indeed useful. Even though you cannot know that the games shown were actually played by other players, each individual player can be sure that his or her own games are correctly shown on that page. As such, if any player notices that his or her own games are not correctly shown, that player can raise a red flag and alert the community.

Sanjay
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 26/11/2012, 07:34:05 UTC
I wonder why the king slice is yellow.  Wouldn't it be better to make it some colour that's different than all the other slices?

http://i.imgur.com/A3uwO.png

Looks to me like you're just showing off that you hit the King slice.  Wink

No, really--thanks. Good feedback. I was going for the King slice to look like "gold," but you're right; it looks too close to yellow. I changed it to purple.

I've fixed the "disappearing button" issue.

Thanks again, dooglus!

Sanjay
Post
Topic
Board Gambling
Re: Kingcoin: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 26/11/2012, 03:48:30 UTC
Updates to Kingcoin

November 25, 2012
Some game parameters have changed to benefit the player.
  • The expected value of Kingcoin has increased to be competitive with other games. It is now approximately 0.984.
  • Game parameters are as follows: Black slice is 16% of the wheel (used to be 15%), King slice is 1.3% of the wheel (used to not exist), and other slices are a minimum of 15% of the wheel (used to be 10%).
  • The maximum number of spins per game is now 5.
  • Each game is logged in the database with more details (in case I have to process refunds)
Post
Topic
Board Gambling
Re: Are bitcoins casinos really pointless?
by
coolidgecoin
on 23/11/2012, 07:48:02 UTC
I started the thread more in the angle, if there is any significant profit for the gambling site owners at this stage if bitcoin economy. Or it's mostly for fun.
In the spirit of transparency and honesty some of them want to set, i'm sure a lot of people will appreciate if they share their profits or at least give us idea about them.
Drugs are the biggest market driver so far, it's logical to expect gambling will be next. But I don't think that's the case here.
(If you could order hookers with bitcoins that would be second)



Hi, Staring Owl-- Obviously, I speak only for myself, but my reason for launching Kingcoin was to learn about Bitcoin, "get my feet wet" with programming Bitcoin, and introduce myself to the Bitcoin community. My profits so far are negligible. Of course, I absolutely want to create a terrific and fun experience for my users, but I see myself eventually doing something more impactful with Bitcoin.

Sanjay
Post
Topic
Board Gambling
Re: Are bitcoins casinos really pointless?
by
coolidgecoin
on 21/11/2012, 20:45:15 UTC
And that comes from the site of the owner of Bodog, so he should know a thing or two?

Two words: House edge.

No, sorry.  Four words.  Add two more: Provably Fair.

Most state-operated lotteries pay out in the range of 70% or less of the lotto ticket/wager revenue.   I don't know the actual number for a fact, but most of these state run lotteries are audited and when you dig you can find their reported results for each jurisdiction.  If you believe they aren't cheating and can trust the audited numbers, you'll probably end up with a number in the 70% range.

BitLotto pays out 99%.   I do know this number to be a fact as I see the blockchain and know exactly how many tickets were purchased.  I can perform the calculation to independently determine the winner, and I see the payout transaction.  Thus I can conclude that player returns when playing BitLotto are 41% higher than when playing MegaMillions (99% versus 70%).
 - http://www.BitLotto.com

SatoshiDICE has a 98.1% payout (before considering transaction fees) which means they keep the 1.9% house edge.  Today I can go through the blockchain and verify that every single wager ever made to SatoshiDICE (ever, like all the way back to their April launch) was calculated correctly and paid out correctly.   I can prove that SatoshiDICE is operating fairly.

In Vegas casinos, the most widely used gambling options (e.g., slot machines) might return maybe 96%, and most are in the 94% or 92% range.   Someone needs to pay for the security cameras, fake volcanoes and free booze.  They only way for a physical casino to function profitably with better odds is likely to cheat somewhere.  (Or so I've read.  I don't gamble much and am not tuned in to the casino industry )

The only reason SatoshiDICE isn't paying out 99% is because they aren't being squeezed by a more aggressive competitor offering a 98.9% payout.   That day will come.  Because with an increase in play, both SatoshiDICE and some other competitor(s) can still operate profitably on a lower house advantage without cheating (which isn't really an option as it would be exposed them and they'ld lose all credibility in a matter of days.)

bitZino doesn't publish the odds to each of their games, I don't believe.  But the odds can be calculated.  For blackjack most of the rule variations are ones that favor the player:
 - http://wizardofodds.com/games/blackjack/rule-variations
 - http://www.bitZino.com

So I can't say that bitZino games (blackjack, video poker, craps and roulette) have  payouts that are higher than a Vegas casino has because I haven't seen the odds (or performed the computations myself) but I would bet that bitZino can always beat Vegas casinos due to having such low costs, on a relative basis.   (Unlike bitLotto and SatoshiDICE, we don't know bitZino's revenues or profits.  I'm going to conclude they are still nowhere near recovering their investment for development but like D&T mentions, they probably didn't build all that intending to profit in 2012 but instead did all that beautiful HTML5 and rock solid back-end work for the returns they could see in 2014 or later, which could be substantial.)

Another provably fair game I'm enthusiastic about is King Coin.  The odds for that were just calculated (thanks doogius) to be in the 96% range.  That makes me less enthusiastic about the game than I was originally, but again, those odds can be increased (which can be verified independently) and hopefully this entertaining visual game can join the stable of online gaming where provably fair gaming using Bitcoins beats any other online gaming options.

And that's what the owner of Bodog either doesn't realize (which I doubt) or wishes to not tout until he figures out a way to make some money from it.  He's welcome to try.  The barrier to entry for building an online casino game is not beyond what a skilled developer operating solo as as "nights and weekends" project can produce.  But with it being provably fair, math gives that alternative the same credibility as what gamers used to count on ...  the polished look and feel that established gaming companies provide.

There's a huge industry that has no idea that they are going to be sharing part of their lunch:
 - http://www.bulletbusiness.com/mobilegambling/index.php


Thanks for the Kingcoin shout-out, Stephen. The URL for those interested is http://kingco.in.

Stephen, I plan to make the game odds better and the game more fun by introducing a jackpot slice with a very high payout. I hope that--along with compatibility on more devices!--will increase your enthusiasm for Kingcoin! I also plan to publish the odds on the site.

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 20/11/2012, 04:01:15 UTC
This is with Chrome browser on Android.  This occurs the same under both a mobile device as well as with a tablet (Nexus 7)

Right now the site is a black hole when using my Android mobile (with Chrome).   The press on the spin button does do a spin and then the spin button reappears.  But the second press causes the button to disappear but no spin occurs.  There is no recovery as far as I could tell.  This occurs when playing for free as well as if I've signed in and have placed an actual wager (and thus the black hole, you will lose your wager).    Something should be done to either disable the game when on a mobile or the game should function on a mobile as well.

My mobile (LG Optimus Elite) is running Android v2.3.7.   Incidentally, this same behavior does not occur on a tablet (Nexus 7) running Android v4.2.




I'll put up a "doesn't work on mobile" redirect of some sort asap. I wanted to get a basic version out there to see what the response was (test the waters) before investing in other platforms. But yes, I should at least have a redirect. Sorry for the poor experience.

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 19/11/2012, 20:21:31 UTC
I just lost .5 playing this game.

It was a combination of freeze outs and delays clicking New Game. If you click it twice too fast it'll steal your bet.


=(




Hi, jjustinn--

First off, I am truly sorry you had trouble with the game. I've refunded your account for the full 0.5 BTC. In addition, I've credited you 0.1 BTC for your troubles. Good luck...hope you win!

In the game log, I see only one game where your game didn't complete possibly due to a slow connection. The other games show a legitimate win or loss.

I haven't been able to reproduce the errors you experienced. Are you on a very slow connection?

Anyway, I've refunded your account with 0.5 BTC (plus 0.1 BTC to aplogize). Please try on a reliable connection and let me know how it goes. On my end, I will simulate a slow connection and add some checks to try and prevent this in the future.

I'm really sorry you had a bad experience and hope you give it another shot.

Thanks,
Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 17/11/2012, 23:00:46 UTC
Also, I ran my simulator on 1 million plays, and show the average payout over each 10k plays.  It seems to suggest the true house edge is more like 4.25%:

Code:
average return over   10000 spins is 0.982250
average return over   20000 spins is 0.971225; average return over last 10000 spins is 0.960200
average return over   30000 spins is 0.972617; average return over last 10000 spins is 0.975400
average return over   40000 spins is 0.967612; average return over last 10000 spins is 0.952600
average return over   50000 spins is 0.968010; average return over last 10000 spins is 0.969600
average return over   60000 spins is 0.965833; average return over last 10000 spins is 0.954950
average return over   70000 spins is 0.963571; average return over last 10000 spins is 0.950000
average return over   80000 spins is 0.960931; average return over last 10000 spins is 0.942450
average return over   90000 spins is 0.960939; average return over last 10000 spins is 0.961000
average return over  100000 spins is 0.960825; average return over last 10000 spins is 0.959800
average return over  110000 spins is 0.959377; average return over last 10000 spins is 0.944900
average return over  120000 spins is 0.958413; average return over last 10000 spins is 0.947800
average return over  130000 spins is 0.958342; average return over last 10000 spins is 0.957500
average return over  140000 spins is 0.959057; average return over last 10000 spins is 0.968350
average return over  150000 spins is 0.958917; average return over last 10000 spins is 0.956950
average return over  160000 spins is 0.959762; average return over last 10000 spins is 0.972450
average return over  170000 spins is 0.960424; average return over last 10000 spins is 0.971000
average return over  180000 spins is 0.960592; average return over last 10000 spins is 0.963450
average return over  190000 spins is 0.960305; average return over last 10000 spins is 0.955150
average return over  200000 spins is 0.959715; average return over last 10000 spins is 0.948500
average return over  210000 spins is 0.960100; average return over last 10000 spins is 0.967800
average return over  220000 spins is 0.960327; average return over last 10000 spins is 0.965100
average return over  230000 spins is 0.960565; average return over last 10000 spins is 0.965800
average return over  240000 spins is 0.960127; average return over last 10000 spins is 0.950050
average return over  250000 spins is 0.959996; average return over last 10000 spins is 0.956850
average return over  260000 spins is 0.959887; average return over last 10000 spins is 0.957150
average return over  270000 spins is 0.959263; average return over last 10000 spins is 0.943050
average return over  280000 spins is 0.959348; average return over last 10000 spins is 0.961650
average return over  290000 spins is 0.959778; average return over last 10000 spins is 0.971800
average return over  300000 spins is 0.959428; average return over last 10000 spins is 0.949300
average return over  310000 spins is 0.959876; average return over last 10000 spins is 0.973300
average return over  320000 spins is 0.959642; average return over last 10000 spins is 0.952400
average return over  330000 spins is 0.959198; average return over last 10000 spins is 0.945000
average return over  340000 spins is 0.959329; average return over last 10000 spins is 0.963650
average return over  350000 spins is 0.959156; average return over last 10000 spins is 0.953250
average return over  360000 spins is 0.958596; average return over last 10000 spins is 0.939000
average return over  370000 spins is 0.958392; average return over last 10000 spins is 0.951050
average return over  380000 spins is 0.958522; average return over last 10000 spins is 0.963350
average return over  390000 spins is 0.958156; average return over last 10000 spins is 0.944250
average return over  400000 spins is 0.957544; average return over last 10000 spins is 0.933650
average return over  410000 spins is 0.957546; average return over last 10000 spins is 0.957650
average return over  420000 spins is 0.957874; average return over last 10000 spins is 0.971300
average return over  430000 spins is 0.958094; average return over last 10000 spins is 0.967350
average return over  440000 spins is 0.958113; average return over last 10000 spins is 0.958900
average return over  450000 spins is 0.958157; average return over last 10000 spins is 0.960100
average return over  460000 spins is 0.957914; average return over last 10000 spins is 0.947000
average return over  470000 spins is 0.957834; average return over last 10000 spins is 0.954150
average return over  480000 spins is 0.957831; average return over last 10000 spins is 0.957700
average return over  490000 spins is 0.957845; average return over last 10000 spins is 0.958500
average return over  500000 spins is 0.958034; average return over last 10000 spins is 0.967300
average return over  510000 spins is 0.958103; average return over last 10000 spins is 0.961550
average return over  520000 spins is 0.957910; average return over last 10000 spins is 0.948050
average return over  530000 spins is 0.958014; average return over last 10000 spins is 0.963450
average return over  540000 spins is 0.958069; average return over last 10000 spins is 0.960950
average return over  550000 spins is 0.958285; average return over last 10000 spins is 0.970000
average return over  560000 spins is 0.957993; average return over last 10000 spins is 0.941900
average return over  570000 spins is 0.957975; average return over last 10000 spins is 0.956950
average return over  580000 spins is 0.958003; average return over last 10000 spins is 0.959600
average return over  590000 spins is 0.958335; average return over last 10000 spins is 0.977600
average return over  600000 spins is 0.958202; average return over last 10000 spins is 0.950400
average return over  610000 spins is 0.958202; average return over last 10000 spins is 0.958150
average return over  620000 spins is 0.958641; average return over last 10000 spins is 0.985450
average return over  630000 spins is 0.958611; average return over last 10000 spins is 0.956750
average return over  640000 spins is 0.958415; average return over last 10000 spins is 0.946050
average return over  650000 spins is 0.958482; average return over last 10000 spins is 0.962800
average return over  660000 spins is 0.958675; average return over last 10000 spins is 0.971200
average return over  670000 spins is 0.958600; average return over last 10000 spins is 0.953650
average return over  680000 spins is 0.958597; average return over last 10000 spins is 0.958400
average return over  690000 spins is 0.958434; average return over last 10000 spins is 0.947350
average return over  700000 spins is 0.958416; average return over last 10000 spins is 0.957150
average return over  710000 spins is 0.958258; average return over last 10000 spins is 0.947200
average return over  720000 spins is 0.958257; average return over last 10000 spins is 0.958200
average return over  730000 spins is 0.958037; average return over last 10000 spins is 0.942200
average return over  740000 spins is 0.958268; average return over last 10000 spins is 0.975100
average return over  750000 spins is 0.958549; average return over last 10000 spins is 0.979400
average return over  760000 spins is 0.958555; average return over last 10000 spins is 0.959000
average return over  770000 spins is 0.958670; average return over last 10000 spins is 0.967400
average return over  780000 spins is 0.958659; average return over last 10000 spins is 0.957800
average return over  790000 spins is 0.958528; average return over last 10000 spins is 0.948300
average return over  800000 spins is 0.958378; average return over last 10000 spins is 0.946550
average return over  810000 spins is 0.958323; average return over last 10000 spins is 0.953900
average return over  820000 spins is 0.958302; average return over last 10000 spins is 0.956650
average return over  830000 spins is 0.958460; average return over last 10000 spins is 0.971400
average return over  840000 spins is 0.958351; average return over last 10000 spins is 0.949300
average return over  850000 spins is 0.958142; average return over last 10000 spins is 0.940600
average return over  860000 spins is 0.957822; average return over last 10000 spins is 0.930600
average return over  870000 spins is 0.957674; average return over last 10000 spins is 0.944950
average return over  880000 spins is 0.957515; average return over last 10000 spins is 0.943700
average return over  890000 spins is 0.957448; average return over last 10000 spins is 0.951500
average return over  900000 spins is 0.957381; average return over last 10000 spins is 0.951450
average return over  910000 spins is 0.957069; average return over last 10000 spins is 0.929000
average return over  920000 spins is 0.957115; average return over last 10000 spins is 0.961300
average return over  930000 spins is 0.957189; average return over last 10000 spins is 0.964000
average return over  940000 spins is 0.957286; average return over last 10000 spins is 0.966300
average return over  950000 spins is 0.957279; average return over last 10000 spins is 0.956600
average return over  960000 spins is 0.957481; average return over last 10000 spins is 0.976650
average return over  970000 spins is 0.957582; average return over last 10000 spins is 0.967300
average return over  980000 spins is 0.957528; average return over last 10000 spins is 0.952300
average return over  990000 spins is 0.957527; average return over last 10000 spins is 0.957450
average return over 1000000 spins is 0.957537; average return over last 10000 spins is 0.958500

Nice analysis! I do plan on lowering the house edge. 4% seems too high relative to other games. I will post to this thread when completed. I might add a special slice on the wheel that is a mega-jackpot (10x or 20x). That will give me an easy parameter to tweak in order to adjust the expected value.

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 17/11/2012, 22:59:07 UTC
Hi, dooglus-- I sent 1 BTC to 146aSkxyXWM4U7jPnsXhVHd1RfohnVDhPx. Enjoy!

Received, thanks.

I played 10 games at 0.1 BTC each:

http://i.imgur.com/07LyB.png

So I kept only 0.6 BTC.  Well less than expected.

I asked to withdraw 0.6 BTC, and it appeared to let me, but some seems to be gotten lost in transaction:

http://i.imgur.com/Q8R7j.png

Yep, I include a very small transaction fee.

About taking only 0.6 BTC, looks like you just got unlucky. Smiley

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 16/11/2012, 17:38:45 UTC
Btw, dooglus, if you sign up for Kingcoin, let me know your receive address and I'll send you 1.0 BTC to play with to say thanks for this analysis!

I just signed up, but I was confused by the interface.  I think I ended up signing up with a blank password.

The signup page doesn't ask for the password twice, like every other signup page in the world does, so I thought it was a login page.  You shouldn't allow people to use blank passwords either, I think.  I can't find any way of changing my password.  Is there a way?

I made another account, this time specifying a password.  Its receive address is 146aSkxyXWM4U7jPnsXhVHd1RfohnVDhPx.

Thanks!

I sped up the simulation code - there's no need to shuffle all 1000 spots on the wheel when we only ever use the first 6.  It's still pretty slow, being written in Python and all, but I got another result:

average return over 100000 spins is 0.961925

Also, I couldn't find a way to get rid of the big grey 'Send to this address to play for real BTC!' box that popped up showing me my deposit address.  Eventually I found a slightly differently grey coloured X somewhere near the top right corner, but not close enough to the corner to really look like a 'close' button.  That closed the dialog, but it's pretty hard to notice it given its low contrast and unusual positioning.

Hi, dooglus-- I sent 1 BTC to 146aSkxyXWM4U7jPnsXhVHd1RfohnVDhPx. Enjoy!

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 15/11/2012, 18:55:14 UTC
According to some simulations I've run, the house edge for this game is around 4%:

average return over 20000 games is 0.965675
average return over 20000 games is 0.951625
average return over 20000 games is 0.961850
average return over 100000 games is 0.960370

Code:
#!/usr/bin/env python

import MersenneTwister19937

import random, string

class KingCoin:
    def __init__(self):
        seed = random.randint(0, 2**60)
        self.mt = MersenneTwister19937.MersenneTwister19937(seed)

        self.FOUR_DIFFERENT = 3 # 4 different colors in 4 spins
        self.SIX_SPINS = 2.5 # 6 spins, any color
        self.THREE_IN_ROW = 2 # 3 in a row
        self.THREE_OF_FIVE = 1.5 # 3 out of 5 (needs 5 non-black spins to pay)
        self.LOSE = 0 # spinning black = lose

    def play_once(self):
        wheel = '1'*3 + '0'*450
        wheel = [150] + map(lambda x: len(x)+100, string.split(self.mt.shuffle_string(wheel), '1'))
        n = 0
        spots = []
        for c in wheel:
            spots += c*[n]
            if (n == 0):
                n += 1
            else:
                n *= 2

        self.spots = self.mt.shuffle(spots)[:6]
        s0, s1, s2, s3, s4, s5 = self.spots

        # 3 spins
        if s0==0 or s1==0 or s2==0: return self.LOSE
        if s0==s1 and s1==s2: return self.THREE_IN_ROW

        # 4 spins
        if s3==0: return self.LOSE
        if s0+s1+s2+s3 == 15: return self.FOUR_DIFFERENT
        if s1==s2 and s2==s3: return self.THREE_IN_ROW

        # 5 spins
        if s4==0: return self.LOSE
        if s1+s2+s3+s4 == 15: return self.FOUR_DIFFERENT
        if s2==s3 and s3==s4: return self.THREE_IN_ROW
        c = {}
        for i in self.spots[0:5]:
            if c.has_key(i):
                c[i] += 1
                if c[i] == 3: return self.THREE_OF_FIVE
            else:
                c[i] = 1

        # 6 spins
        if s5==0: return self.LOSE
        if s2+s3+s4+s5 == 15: return self.FOUR_DIFFERENT
        else: return self.SIX_SPINS

k = KingCoin()

spins = 100000
sum = 0.0
for i in range(spins):
    sum += k.play_once()

print "average return over %d spins is %f" % (spins, sum / spins)

Btw, dooglus, if you sign up for Kingcoin, let me know your receive address and I'll send you 1.0 BTC to play with to say thanks for this analysis!

Thanks,
Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 15/11/2012, 08:02:34 UTC
Does "red, red, yellow, red, red" count as a "3 out of 5" win?  It's a 4 out of 5, so I can imagine you might not count it as a win, though that would seem a little harsh.

Yes, that would count as a "3 out of 5 win". Per the official rules:

"3 out of 5: Hit the same color in any 3 of the previous 5 spins. Note that this winning pattern can only be achieved after the wheel has been spun at least 5 times."

I do not say "exactly 3 of the previous 5." But still, good question.

Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 15/11/2012, 08:01:00 UTC
According to some simulations I've run, the house edge for this game is around 4%:

average return over 20000 games is 0.965675
average return over 20000 games is 0.951625
average return over 20000 games is 0.961850
average return over 100000 games is 0.960370

Code:
#!/usr/bin/env python

import MersenneTwister19937

import random, string

class KingCoin:
    def __init__(self):
        seed = random.randint(0, 2**60)
        self.mt = MersenneTwister19937.MersenneTwister19937(seed)

        self.FOUR_DIFFERENT = 3 # 4 different colors in 4 spins
        self.SIX_SPINS = 2.5 # 6 spins, any color
        self.THREE_IN_ROW = 2 # 3 in a row
        self.THREE_OF_FIVE = 1.5 # 3 out of 5 (needs 5 non-black spins to pay)
        self.LOSE = 0 # spinning black = lose

    def play_once(self):
        wheel = '1'*3 + '0'*450
        wheel = [150] + map(lambda x: len(x)+100, string.split(self.mt.shuffle_string(wheel), '1'))
        n = 0
        spots = []
        for c in wheel:
            spots += c*[n]
            if (n == 0):
                n += 1
            else:
                n *= 2

        self.spots = self.mt.shuffle(spots)[:6]
        s0, s1, s2, s3, s4, s5 = self.spots

        # 3 spins
        if s0==0 or s1==0 or s2==0: return self.LOSE
        if s0==s1 and s1==s2: return self.THREE_IN_ROW

        # 4 spins
        if s3==0: return self.LOSE
        if s0+s1+s2+s3 == 15: return self.FOUR_DIFFERENT
        if s1==s2 and s2==s3: return self.THREE_IN_ROW

        # 5 spins
        if s4==0: return self.LOSE
        if s1+s2+s3+s4 == 15: return self.FOUR_DIFFERENT
        if s2==s3 and s3==s4: return self.THREE_IN_ROW
        c = {}
        for i in self.spots[0:5]:
            if c.has_key(i):
                c[i] += 1
                if c[i] == 3: return self.THREE_OF_FIVE
            else:
                c[i] = 1

        # 6 spins
        if s5==0: return self.LOSE
        if s2+s3+s4+s5 == 15: return self.FOUR_DIFFERENT
        else: return self.SIX_SPINS

k = KingCoin()

spins = 100000
sum = 0.0
for i in range(spins):
    sum += k.play_once()

print "average return over %d spins is %f" % (spins, sum / spins)

Wow, impressive! I did some simulations myself and got virtually the same figures. Thanks for doing this!
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 13/11/2012, 23:13:14 UTC
I welcome any and all feedback! I plan to make the game even more fun by introducing a daily jackpot, so stay tuned.


There's still this issue, with Android:

from an Android mobile when I login, the logout button isn't clickable for some reason.

The only way to logout is to get to a 0 balance and then a link for logout is shown.

Ack, my apologies. It's designed for Chrome and Firefox only. I'll add a message on the site about this.

Thanks,
Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 13/11/2012, 23:12:26 UTC
I welcome any and all feedback! I plan to make the game even more fun by introducing a daily jackpot, so stay tuned.

I like it.  I only played play money, but didn't do very well.

Do you have any idea what the house edge is?

Hi, dooglus-- It is actually very difficult to compute the house edge because the color slices are of random and variable sizes each game. If Kingcoin becomes popular, I'll figure out the precise odds and post.

Each game, the minimum size of each slice is 10% of the total wheel. The black slice is a constant 15%. The wheel is spun randomly (per the seeds, which are provided by the user but otherwise based on a timestamp), but the precise same location cannot be hit twice (because the wheel is represented as a randomized string of integers (each slice represented by one integer), and the first 6 integers of the string are the outcome of each game).  I believe that is all there is to the game!

I'm glad you like the game!

EDIT: Forgot to mention one more thing. I publish each and every paid game's outcome at http://kingco.in/history.php

Thanks,
Sanjay
Post
Topic
Board Gambling
Re: A delightfully simple spin-the-wheel game (that's provably fair)
by
coolidgecoin
on 13/11/2012, 23:06:26 UTC
It appears there is no memory of games that have started.  

Specifically, let's say a browser crashes in the middle of a spin.  The funds are lost.  I can log out and log back in and my funds are lost and it is looking for me to start a new game.  I don't see any way to resume from where the crash occurred.  

(This happened to me after starting to play with some newly deposited coin.)

Hi, Stephen-- Let me know how much you lost and your address and I'll refund you. You are right; as of now, you must finish a game once you start it, otherwise you lose the game. I will change this if Kingcoin becomes popular, but right now it seems to be a corner case that probably doesn't merit the time needed to fix.

I do log every game, wager, and outcome (as well as all items required for provability) in my database once the game has started. So even if your browser crashes mid-game, I have a record of it.

EDIT: I apologize for the inconvenience, Stephen!

Thanks,
Sanjay