Just-Dice.com : Invest in 1% House Edge Dice Game

[r3demon]

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

[1714181220]

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[mechs]

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

[tucenaber]

some investors will wait ages to recover their losses as everyone will invest back now  

Exactly, those who stayed are going to wait ages for recovery, while those who left and go back now are going to benefit from the lower variance! Insane.

Yes, that's me. Kinda hurts to know that even dooglus divested, plus he suddenly changed the rules while the only customers that could have made us quickly recoup those losses was playing, pissing him off big time.

I was ready to lose 100% of my investment playing against Nakowa because I have faith in both math and the weaknesses of gambler psychology, but realizing that it will now take ages to recoup that investment because of a management decision really sucks.

Includes me as well. I'm not happy about this.

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

The house was never in any danger of going bust. That's the beauty of the Kelly criterion. You nevere risk more than 1%.

[integrity42]

btw, the worst thing - for JD and remaining investors- is that nakowa will lose his money somewhere else.
no way he just stops

+1 trout!!!!

I think this move eroded gamblers confidence in the site...

This is what is going through big players/whales heads right now:

Whale: "Hmmm, I was going to play at just-dice, but I heard they randomly change the max bet at any time without notice.  I might lose 2,500 BTC playing at X BTC bets, and then they'll just drop the max bet without notice to 1/2!  I'll never be able to recover.  Way to risky to play there. I'll take my business somewhere else."

Really bad idea to do this with no notice.  Investors who stayed invested with 30,000 BTC and took the loss from Nakowa won't ever see it back.

[cbhelp]

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

This is ridiculous.

The edge should be the same for any bets.  Period.  If you dont want the swings, dont open a casino.

Its a gamble.  Not "lets jack up the odds for a big bet because we are scared"

[Jls.]

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

What ? Nothing is set in stone as of now (or I missed something ?).

1 - you're not the boss.
2 - you may have a massive investment on JD, but i doubt you weight more than 50%.

[aahzmundus]

Doog, Could you generate a stat for me?  Average wagered per day over the last 7 days ignoring Nakowa?  I would basically like to see if all this news has brought traffic to the site or not, specifically betting traffic, but it is hard to tell with any data I have access to.

[oda.krell]

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

This is ridiculous.

The edge should be the same for any bets.  Period.  If you dont want the swings, dont open a casino.

Its a gamble.  Not "lets jack up the odds for a big bet because we are scared"

Disagree. As I said before, I could imagine a simple 2-tier system: 1% for bets up to 50btc, 1.5% or 2% for higher bets.

Advantages: easy to understand, so probably won't chase away many customers, and will reduce the wild swings we've seen.

Personally, I'd say go back to 1% max bet. But I'm not absolutely commited to that one...

[integrity42]

Everyone is overlooking something!!

As USD/BTC rises over time, Bet sizes will drop.

This happened with Satoshi-dice.

Chances are if the exchange rate starts rising quickly, we'll never see 6,000 BTC profit again.

If we don't let nakowa play at 1% and win back the losses, investors who put in money at 1% will be permanently screwed.

[cbhelp]

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

This is ridiculous.

The edge should be the same for any bets.  Period.  If you dont want the swings, dont open a casino.

Its a gamble.  Not "lets jack up the odds for a big bet because we are scared"

Disagree. As I said before, I could imagine a simple 2-tier system: 1% for bets up to 50btc, 1.5% or 2% for higher bets.

Advantages: easy to understand, so probably won't chase away many customers, and will reduce the wild swings we've seen.

Personally, I'd say go back to 1% max bet. But I'm not absolutely commited to that one...

I guess a casino should pay half what a blackjack is worth if you bet over a certain amount also huh. Or if you bet 5.00 on red you win 10.... But if you bet 100.00 u only won 195.00

[Ekonom]

Different house edge for whales totally suck. It's just not fair. (I'm saying that as an investor) Let's find the right amount of max profit instead please..

[rdponticelli]

some investors will wait ages to recover their losses as everyone will invest back now  

Exactly, those who stayed are going to wait ages for recovery, while those who left and go back now are going to benefit from the lower variance! Insane.

Yes, that's me. Kinda hurts to know that even dooglus divested, plus he suddenly changed the rules while the only customers that could have made us quickly recoup those losses was playing, pissing him off big time.

I was ready to lose 100% of my investment playing against Nakowa because I have faith in both math and the weaknesses of gambler psychology, but realizing that it will now take ages to recoup that investment because of a management decision really sucks.

Includes me as well. I'm not happy about this.

The whale showed us that large bets are risky for the house. Why not to change house edge with a bet size? So that someone could bet even 1000 bitcoins at once, but with a house edge like 20-30%.

The house was never in any danger of going bust. That's the beauty of the Kelly criterion. You nevere risk more than 1%.

Count me between the unhappy ones. We were already voting with our wallets, by staying invested. This unilateral decision has screwed everybody. Gamblers and investors.  

[integrity42]

19:48:23 (2548) <nakowa> WITH ALL DUE RESPECT, NO ONE WANT TO PLAY IN A CASINO THAT CHANGES RULES WITHOUT WARNING PLAYERS. IT'S UNFAIR

Straight from the whales mouth.

[oda.krell]

I guess a casino should pay half what a blackjack is worth if you bet over a certain amount also huh. Or if you bet 5.00 on red you win 10.... But if you bet 100.00 u only won 195.00

Your comparison fails. A random casino also will send someone to break your kneecaps refuse a customer who they fear to possess a bankroll as large or larger than their own.

Plus, what's with the "principles"? Are we following the holy bible of casino morals? Hint: we're not. We should do what both interesting for players and profitable for investors. That's all.

[jlcooke]

Let's consider nakawa has some information on a weakness of SHA-512.

http://en.wikipedia.org/wiki/Hash-based_message_authentication_code
 

Code:

HMAC-SHA512(K,m) = SHA512((K ⊕ opad) + SHA512((K ⊕ ipad) + m))

+ is concatenation
 ⊕ is exclusive-or

PHP Code to compute the lucky number:

Code:

function getLuckyNumber($server, $client, $nonce) {
   $str = hash_hmac("sha512", "$client:$nonce", $server);

   for ($i=0; $i<strlen($str); $i+=5) {
      $hex = substr($str, $i, 5);
      $dec = hexdec($hex);
      if ($dec < 1000000)
         return $dec / 10000;
   }
}

The SHA-512 compression function uses 80 x 64-bit words (5120 bits) plus the 8 x 64-bit (512 bits) state words to output 8 x 64bit (512 bits).

That means the final outer hash of the HMAC-512 bits
 - size of server seed (K here) is 64 characters [0-9A-Za-z\._]  (512 bits, 384 bits maximum entropy)
 - client seed is usually 24 characters (192 bits) (is there a minimum?  maximum?)
 - nonce can be 1,2,3,4,etc charactors.  Lets assume 1..4 (32bits) based on nakowa's pattern of behaviour.

That means:

Code:

 HMAC-SHA512(K,m) = SHA512( <512 bits> + <512 bits> + <192 bits> + ':' + <32 bits> ) 

If there was an attack via the SHA-512 compression function, it would be by exploiting the fact that bits 1024...1215 (bytes 128...151) are totally under client control and bits 1216...1247 (bytes 152...155) are totally predictable (sequential).

So let's look and see if nakowa's bets vary based on the bits of his nonce (it's been shown he hardly ever changes his client seed, so let's focus on the nonce).

PHP code for others to take and improve:

Code:

<?php

if (!function_exists("stats_standard_deviation")) {
   print "need to install stats package\n".
      "pecl install stats\n".
      "echo extension=stats.so > /etc/php.d/stats.ini\n";
   exit;
}

// Source data
// https://just-dice.com/nakowa.txt.bz2
// https://just-dice.com/nakowa2.txt.bz2

$fh = fopen("nakowa.txt","rb");
if (!$fh) {
   exit;
}

# remove headers
$line=fgets($fh); $line=fgets($fh); $line=fgets($fh);

# init our counts
$sum = 0;
$gray_bets = array();
resetGrayBets($gray_bets);

// reset sums
function resetGrayBets(&$gray_bets) {
   $bits = 12;

   // 1 bit
   for ($i=0; $i<$bits; $i++)
      $gray_bets[1 << $i] = array();

   // 2 bits
   for ($i=0; $i<$bits; $i++)
   for ($j=$i+1; $j<$bits; $j++)
      $gray_bets[(1 << $i) | (1 << $j)] = array();

   // 3 bits
   for ($i=0; $i<$bits; $i++)
   for ($j=$i+1; $j<$bits; $j++)
   for ($k=$j+1; $k<$bits; $k++)
      $gray_bets[(1 << $i) | (1 << $j) | (1 << $k)] = array();

   // 4 bits
   for ($i=0; $i<$bits; $i++)
   for ($j=$i+1; $j<$bits; $j++)
   for ($k=$j+1; $k<$bits; $k++)
   for ($l=$k+1; $k<$bits; $k++)
      $gray_bets[(1 << $i) | (1 << $j) | (1 << $k) | (1 << $l)] = array();

#  ksort($gray_bets);
}

// display sums
function dumpGraySums($gray_bets) {
   $report = array();

   foreach ($gray_bets as $i=>$arr) {
      $ibin = substr("00000000000000000". decbin($i), -16);

      if (count($arr) == 0)
         continue;

      $sum = $mean = $stdev = 0;
      if (count($arr) != 0) {
         $sum = array_sum($arr);
         $mean = $sum / count($arr);
         $min = min($arr);
         $max = max($arr);
         $stdev = stats_standard_deviation($arr);
      }

      $report[] = array(
         'i' => $i,
         'ibin' => $ibin,
         'sum' => $sum,
         'count' => count($arr),
         'mean' => $mean,
         'min' => $min,
         'max' => $max,
         'stdev' => $stdev,
      );
   }

   usort($report, function($a,$b){
      return $b['mean'] - $a['mean'];
#     return $b['stdev'] - $a['stdev'];
   });

   foreach ($report as $i=>$info) {
      $info['sum'] = sprintf("%4.3u", $info['sum']);
      $info['count'] = sprintf("%4.3u", $info['count']);
      $info['min'] = number_format($info['min'], 3);
      $info['mean'] = number_format($info['mean'], 3);
      $info['max'] = number_format($info['max'], 3);
      $info['stdev'] = number_format($info['stdev'], 3);

      print " {$info['ibin']}: sum={$info['sum']}, count={$info['count']}, min/mean/max={$info['min']}/{$info['mean']}/{$info['max']}, stdev={$info['stdev']})\n";
   }
}

$last_nonce = -1;
while (($line=fgets($fh)) !== false) {
   list($uid,$bid,$nonce,$bet,$chance,$profit) = preg_split('/\t/', $line);

   // cast to int
   $uid = (int)$uid;
   $bid = (int)$bid;
   $nonce = (int)$nonce;
   $bet = (int)$bet;
   $change = (int)$change;
   $profit = (int)$profit;

   if ($last_nonce == -1)
      $last_nonce = $nonce;

   if ($bet == 0)
      continue;
   // values in BTC
   $bet /= 100000000;
   $profit /= 100000000;

   $nonce_bin = substr("00000000000000000". decbin($nonce), -16);

#  if ($bet >= 10)
      print "$uid\t$bid\t$nonce\t$nonce_bin\t{$bet}BTC\t$chance\t{$profit}BTC\n";

   $sum += $profit;
   foreach ($gray_bets as $code=>$ignore) {
# edit-1 start
      if      ($nonce < 0x0000100) $nonce_bytes = $nonce << 24;
      else if ($nonce < 0x0010000) $nonce_bytes = $nonce << 16;
      else if ($nonce < 0x1000000) $nonce_bytes = $nonce <<  8;
      else                         $nonce_bytes = $nonce;

      if (($nonce_bytes & $code) == $code) {
#edit-1 end
         $gray_bets[$code][] = $bet;
      }
   }

   if ($nonce < $last_nonce) {
      print "sum = $sum\n";
      dumpGraySums($gray_bets);

      $sum = 0;
      resetGrayBets($gray_bets);
   }
   $last_nonce = $nonce;
}

dumpGraySums($gray_bets);

Running this against nakowa.txt from just-dice.com there is no discernible favouring of certain bits over others.

So if there is some evil crypto genious behind nakowa's streak, this isn't the angle.

Edit: updated PHP code - bug.

[mechs]

I guess a casino should pay half what a blackjack is worth if you bet over a certain amount also huh. Or if you bet 5.00 on red you win 10.... But if you bet 100.00 u only won 195.00

Your comparison fails. A random casino also will send someone to break your kneecaps refuse a customer who they fear to possess a bankroll as large or larger than their own.

Plus, what's with the "principles"? Are we following the holy bible of casino morals? Hint: we're not. We should do what both interesting for players and profitable for investors. That's all.

+1

[mechs]

That the plan - the max profit limit a stopgap measure only.  He will be raising the house edge gradually for bets over 50 BTC.  Will remain 1% for those 50 BTC and below

What ? Nothing is set in stone as of now (or I missed something ?).

1 - you're not the boss.
2 - you may have a massive investment on JD, but i doubt you weight more than 50%.

That was the plan Dooglus mentioned to me.  It could change.  I can only offer my advise, he is a smart guy and the decision is his alone.

[cbhelp]

I guess a casino should pay half what a blackjack is worth if you bet over a certain amount also huh. Or if you bet 5.00 on red you win 10.... But if you bet 100.00 u only won 195.00

Your comparison fails. A random casino also will send someone to break your kneecaps refuse a customer who they fear to possess a bankroll as large or larger than their own.

Plus, what's with the "principles"? Are we following the holy bible of casino morals? Hint: we're not. We should do what both interesting for players and profitable for investors. That's all.

Actually...your comparison fails.

You said it, they can refuse service.  But they DO NOT change the odds.  And jd can refuse service also. Lower max bet.  As they did.  

To change the odds is dumb and totally unfair.  That's the same as me betting on a nfl game, at even money, but after my team takes a 21 point lead, the sportsbook decides that the odds are going to be -30 instead, in the middle of the game.


As for your principals comment. Really?  So you advocate the site to be careless with morals?  Because I'm sure THAT will make people gamble there.  You shouldn't post, honestly, unless you think before talking.

[Sterling]

I don't get it.

Nakowa would have lost FAR more today had the max bet remained 1%. How is this unfair?

Was it a rushed decision? Sure. Unfair? Hell nahhh.

[joesmoe2012]

I have to agree that changing max bet and such mid-play without any prior discussion or even notification to investors and gamblers alike was unreasonable.