Ok, so what's wrong with the simple standard fstream usage from that snippet I mentioned? I think simple is best

But if you are already using features from boost::filesystem you can use copy_file from that. I just think that, if not already required for something else, it's a tad overkill.

Don't get me wrong here, you obviously know way more than I do about this, but just indulge me for a little longer if you can.

You say buy every ticket not taken so all dups are working for you, but then you show math where you buy *all* the tickets and only one other is bought. On top of that you assume the one duplicate ticket is not the winner. This is where I think things go crazy, as we're talking about optimal situations which are not, I believe, remotely real. If you don't buy every ticket then the chances of ever winning the prize get substantially smaller and not every ticket is the same.
There's 1 change in 16 for everybody to share 25% of the pot, and 1 in 256 of sharing another 25%. So if I buy 256 tickets wisely chosen to cover all 2 digit combinations, I have secured 15 64BTC in 3rd prizes and 68BTC in 1 2nd. Not enough to cover my bet, so you actually make a profit unless I hit first prize, which I have a 4% chance of doing...

I just proved your point, didn't I?

Damn...

So what can I do to deter this? add a number?

Right, that and the full list of *active* bets should be all the disclosure needed... thanks!

I get all that, the tendency to balance. It just doesn't apply on a small timescale (within a few years small) when you get one draw per week. It might, and it might just have you loose every single time. You play poker, you know about probabilities, and yet it's not the math wizard that makes it to the high stakes tables, it's the guy who can read other people's behavior and uses that to get some leverage.


That is just wrong. Your bets go to the pot in full, but you don't take the whole pot if you win. Poker? sure, but not lottery. The first ticket gives you a chance of winning, at best, 0.5BTC, and it did cost you 1BTC. The second? in a perfect world an extra 0.24, so you are not even making up for the initial bet. It only levels out because many people play and, if you were to make no duplicates, the bets would be spread so well that prize distribution would suck even more.

But I get it, eventually you'll bet, as well as many others and only you will win, making up for all the other losses. I say go for it! The more the merrier...

Ok, ran some numbers, made a few bogus attempts with past data, seems like a good bet, but I have one problem I need some help with: How am I going to give the better some assurance I'm not cheating?

In the lottery I give out all bets before the result is known, so I can't make up numbers after the fact, but here I don't know... I could just show all bets all the time but that would still not prevent me from adding a winning bet a second before the block arrives... don't know what I can do here, other than say 'trust me', which is all fine but, I don't know, feels weird.

It does, noone is arguing that, I believe. It's your assumptions that are slightly off

There was this statistics professor that started the first year class with the following pearl about averages (loosely translated):

"Statistics are like a bikini, showing almost everything but hiding the most important... If you and me both go and eat together, I eat two chiken and you eat none, on average we each had one, but I'll be stuffed and you'll be hungry."

The error, in my non educated opinion, is one of historical averages. Take the coin toss example:

you throw a coin 10 times, 8 of them it falls on tails. What would you say your chances are of hitting tails the 11th throw?

Amazingly, they are 50%. Every time 50%. Regardless of how many times you throw them. This is not true for a physical coin, as it may have unbalanced weight or whatever, but still the same applies.

You are assuming that if you keep betting all numbers all the time, chances are that your losses and your gains will accumulate to void one another. Each time you bet is a different time, same possibilities regardless of past prize history. It's a gamble, no matter how you dice your numbers (pun obviously intended)...

You can minimize you chances of loosing by betting less or not at all, but your chances of winning depend on all the betters, not just on your own actions.

Alright, I propose we vote:

a) Cancel tickets:
  1) remove completely
  2) allow for 100 blocks after ticket registration
  3) allow till draw locked

b) Other bets visibility
  1) only show when draw is locked
  2) show but don't state number of duplicates
  3) show everything, all the time

c) Unclaimed prizes
  1) Just roll over to the next draw
  2) Just add to the prizes actually won on the same draw
  3) do 1) but when pot reaches 5000 (or some other number) do a special "Guaranteed Jackpot!" which is just 2) above

d) bet price
  1) 1
  2) 2
  3) 5
  4) depends on the pot that rolled over (assumes c:1) or c:3) )

e) draw interval
  1) every 1k
  2) every 1k
  3) every 1k, but if c:3) the Guaranteed Jackpot happens in 500 blocks, just to force people to pay attention to the site
  4) every other 0.5k

Share your thoughts!

Oh no, you were clear. It's just the unspoken assumption that if you bet on uncovered numbers you'll win (and thus profit) that I find somewhat misleading

Fixing your sentence:

You bet on uncovered numbers and if you happen to win, and the chances increase with the number of bets you cover profit from when people duplicate each other, knowing that the profit will be reduced and may actually be a loss even when you win as your number of bets increase. If someone lands on you, you take your bet down (while canceling lasts ).

Hey, I like that! I'll put some thought into it and maybe we'll have a test fest soon... Great idea!

Except there's statistical advantage in doing that, unless the number of of 'other betters' is very low, and that defeats the monetary advantage, right?

I mean, if there are few uncovered numbers, your investment is small, payoff potentially big, chances of getting it small.
If there are many uncovered numbers your investment is that much bigger, chances go up in accordance and the payoff just gets smaller

In any case there is absolutely no guaranteed return of investment, mainly because you're not investing It's a bet and what you bet on, how much you bet is only one part of the equation. The other part, what other people do, affect you greatly and you have little or no control over... maybe you can influence other betters, but that's that.

My idea here was; I'm waiting for 2 confirmations, which can take 20 minutes or so. A new user comes in, makes the transfer and wants to play, but can't coz the coins are in transit. He can come back, sure, or he can bet (random 10, in your example) and as soon as the coins arrive the system places the bets. This was supposed to be part of a bigger plan, an auto better, so you can leave an open bet to be played on each draw, if you go on vacations

But I see no harm in removing that, sure. I would then remove the pending and the cancel, is everyone ok with this?

My argument is that if a considerable number of people bet less than you, say 200 bets of 20, chances are you'll be dividing the amount you put in with them, thus effectively doing charity for all the winners

As a  side note, this was part of the decision of letting unclaimed prizes roll over to next draws, giving them higher jackpots or, alternatively, using the full bet pot on the current draw, blending in unclaimed prized with the for for those actually claimed.

In the latter approach, betting all possibilities would, I believe, be even more harmful, as in the former at least there's an accumulated jackpot to add as incentive to your bet.

How about instead of a blind draw, I still allow you to see bets, and those that you made BUT not duplicates? Each bet appears exactly once. Then, when the draw is locked, full bets appear and are downloadable for auditing.

In the spirit of full disclosure, the canceling of bets is a safety feature... for me

It was never intended to be used in the spirit of "I will bet, because I can cancel", but rather as a fallback if you happen to have 1000 pending tickets and instead of sending 10 BTC you send 1000... this way I don't have to manually go and fix it for you.

Now, I can completely remove the bet cancel, or I can put a timer on it. Bets can be canceled up to 100 blocks from when they were registered? so you have a margin, but there's no analogy to 'chargeback' behavior in the lottery.

It has just occurred to me, should I not lock canceling bets in the couple of days that precede the draw? I mean, I could put 2000 coins in just to drive people to bet more and then retract 1950, which would lead to a much lower pot, but eventually much bigger for me than it would be without the bait.

I would still allow bets to be put up to 6 blocks (~1hour) before the draw conclusion, but would lock canceling maybe 25% through the draw? say 250 (~1.25 days) blocks for a 1000 block draw interval?

I won't do it on this draw, as it is almost up *and* I hold most of the bets, which I will not retract, but for the next one?

That is the way things are implemented One ticket, the highest prize.

Right! We have enough pyramids already, so I'm going down the viral path...

So every time I get one I pay 3, it's just a pitty so few have joined so far, I'm already repeating addresses.

It's a sad thing, this society we live in that so easily puts a price tag on our chicken. How can we do that and sleep at night?

Well, it's well deserved if you do. Your help, and that of TTBit has been most refreshing.

But... you do realize that now, with the added 150, the odds are totally on my side, right? :-)

Lotteries are all about masses. Lots of betters == more for the winners.

I guess I couldn't expect a flood of bets right from the start, so we need to get the word out. I didn't want to just spread the word like wildfire because this is very experimental and I can only cover for so much if things go bad

But lets get some numbers out: The largest better has 26 BTCs in the draw which is 20% of the total bets, the 2nd and 3rd prize pools are at 28, so that doesn't make it very interesting. First prize is 60, for less than 1% chance of getting it, not very interesting.

I'm guessing a tenfold increase in the bets (so for 1200 total prize pool) things would get interesting. This would only happen if we see a tenfold increase in betting, which at this point is not very much likely, or we get some from the previous draws. I can, and will, make the pool of unclaimed prized blend in to the current pool if everyone really just wants to get a cut and be done with it, but I really think it would be much better to let the prize pool for the next one grow, this all assuming noone gets 1st prize, of course

With all that, I'm going to bet an extra 150 BTC and any prize I get from that I'll use to bet again on the next draw, just to kick up interest a notch. I will need to make a decision on the unclaimed prize distribution today, so speak up now. I'm still very much biased to moving unclaimed to the next draw as initially planned.