Introducing: The Amazing Anonymous Bitcoin Lottery

[nelisky]

Bitcoin Watch has implemented a way to check all details of a block, including the hash we will be using for the lottery:

http://bitcointalk.org/index.php?topic=928.0

This is a good way of confirming the result is correct for users that don't wan't to/can't recompile bitcoin with getblock. Now you don't have to take my word for it

Major thanks to Bitcoin Watch.

[1715042126]

1715042126

[TTBit]

Maybe if there is no 1st place winner, the 1st place win pool goes into the 2nd place win pool. If no 2nd place winner, down to 3rd place, etc. This might get more people in invest in the lottery in the early stages, rather than just wait until there are thousands of btc up for grabs, and not such a losing proposition.

That's a pretty good idea, I think I prefer it to the rollover.

But what about in the long run? You don't want to see very large jackpots there?

You are the ones in charge though, if you prefer blend down to rollover I'll just do it... but read my previous post, might be a good middleground.

I guess we do lose that building excitement factor. Now I don't know what I like. I'll think a while.

That last thing you suggested is a bit complicated, I'll read it again, but you don't want to put people off with overly intricate rules. (Maybe I'm just slow too, I'll reread)

Yeah, i'm back to leaving as-is I think. This is fun and charitable for me, not hoarding my precious coins. A large jackpot would grow the bitcoin community much faster. 360 to go!

[need signature of lottery details]

[nelisky]

That last thing you suggested is a bit complicated, I'll read it again, but you don't want to put people off with overly intricate rules. (Maybe I'm just slow too, I'll reread)

It's not as complicated as it may seem at first read. Basically it's just making sure the whole cake is distributed on that draw, regardless of there being no 1st prizes.

I like the 1000 / 2BTC + 500 / 5BTC for those 'guaranteed jackpot' idea... would that deter you from playing?

Yeah, i'm back to leaving as-is I think. This is fun and charitable for me, not hoarding my precious coins. A large jackpot would grow the bitcoin community much faster. 360 to go!

[need signature of lottery details]

sig of lottery details... hmmm, that's a great idea.

* nelisky pushes sig to top of todo list

[FreeMoney]

I guess in my excitement I didn't ever worry about how bad of a deal buying the first tickets is. When there is no pot you are essentially buying a small chance of getting your money back or less. That's fine right now when we buy tickets out of novelty and lack of alternatives, but it will wear off. This leads me to think we need to return all or almost all of the money to users each time. Maybe hold back ~5% each time and let that accumulate or something.

So until I change my mind again (coming soon) I'm in the "pay it all out" camp. This should still cause pots to grow over time since winners will throw back in, and stories of great bit-riches will get spread around.

[nelisky]

I guess in my excitement I didn't ever worry about how bad of a deal buying the first tickets is. When there is no pot you are essentially buying a small chance of getting your money back or less. That's fine right now when we buy tickets out of novelty and lack of alternatives, but it will wear off. This leads me to think we need to return all or almost all of the money to users each time. Maybe hold back ~5% each time and let that accumulate or something.

So until I change my mind again (coming soon) I'm in the "pay it all out" camp. This should still cause pots to grow over time since winners will throw back in, and stories of great bit-riches will get spread around.

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.

[FreeMoney]

I guess in my excitement I didn't ever worry about how bad of a deal buying the first tickets is. When there is no pot you are essentially buying a small chance of getting your money back or less. That's fine right now when we buy tickets out of novelty and lack of alternatives, but it will wear off. This leads me to think we need to return all or almost all of the money to users each time. Maybe hold back ~5% each time and let that accumulate or something.

So until I change my mind again (coming soon) I'm in the "pay it all out" camp. This should still cause pots to grow over time since winners will throw back in, and stories of great bit-riches will get spread around.

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

Totally.

A lottery with 1 person buying 1 ticket is boring no matter what.

I'm just saying that from the perspective of early ticket buyers it's a pretty terrible deal. For simplicity pretend it is winner take all. You buy a ticket for 1BTC that has a 1/4096 chance of getting you like 1 or 20 or 100 or even 1000BTC, it's not anywhere near even money. Now this just means that money will probably roll over making future draws more attractive. As long as you have an ample supply of people buying when it's a terrible deal, there's no problem because once they get it started it turns out not to be a bad deal. I'm just mentioning the possibility of everyone saying, "eh, I'll wait to see if this is going to get big at all". Now with the ability to unbuy tickets like you have it is less of a commitment so maybe people will say "I'll grab some numbers now and just cancel if it seems too small" then other people see it is growing and 'ta-da' we have a good pot.

These are just some thoughts, all that really matters is what people actually like. And that is hard for me to guess.

Thanks for the 150, I'm totally going to win it. :-)

[nelisky]

Thanks for the 150, I'm totally going to win it. :-)

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? :-)

[FreeMoney]

Thanks for the 150, I'm totally going to win it. :-)

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? :-)

I've still got a few days to throw some more down ;-)

I just noticed you can buy 10kBTC on MtGox and only move the price 2%. Sick market.

[TTBit]

question:

If I bet  'ABC' and it hits, I win the 1st place prize. But do I also get a cut of 2nd and 3rd? Same thing if I bet 'FBC' and the winner is 'ABC', I get 2nd and 3rd or just 2nd?

I vote 1 ticket 1 prize if easy to implement.

[nelisky]

question:

If I bet  'ABC' and it hits, I win the 1st place prize. But do I also get a cut of 2nd and 3rd? Same thing if I bet 'FBC' and the winner is 'ABC', I get 2nd and 3rd or just 2nd?

I vote 1 ticket 1 prize if easy to implement.

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

[nelisky]

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?

[TTBit]

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?

yes. retracting bets stinks. But I think you'll run into the problem of people being upset if they find out there are 4 bets on their number, and can't retract. If retraction is out, consider a blind draw, just make all picks public 6 blocks before the pick.

[nelisky]

Why not only allow someone to withdraw bets that are chosen multiple times?

Once a bet is chosen, I don't see why they should be able to retract it at all. If you typed the wrong number, pay another coin and buy the one you wanted to.

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.

[nelisky]

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?

yes. retracting bets stinks. But I think you'll run into the problem of people being upset if they find out there are 4 bets on their number, and can't retract. If retraction is out, consider a blind draw, just make all picks public 6 blocks before the pick.

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.

[nelisky]

How about your can't buy a ticket unless you have enough BTC to fund it? Why not require them to have a BTC for them to buy a ticket... ?? Then if they transfer in 1000 BTC and only want to buy 10 tickets... they only type in 10 numbers.

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?

[jgarzik]

Another possible lotto variant is a pick-3 or pick-4 or whatever, where you require 100% match, but have a drawing for each bitcoin block.  Jackpot keeps growing, and all tickets remain valid, until a winner emerges.

Somewhat like "sudden death overtime" in sport, where you keep playing until someone scores.

[nelisky]

Another possible lotto variant is a pick-3 or pick-4 or whatever, where you require 100% match, but have a drawing for each bitcoin block.  Jackpot keeps growing, and all tickets remain valid, until a winner emerges.

Somewhat like "sudden death overtime" in sport, where you keep playing until someone scores.

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

[nelisky]

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!

[TTBit]

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!

a) 1) Maybe only allow 5 bets at a time, so no 'whoopsies I bet 500 coins'.
b) 1) Don't allow duplicate bets? If its crowded, up to 4 chars.
c) 2) No unclaimed prizes.
d) 1) 1 btc
e) Every X draws, 1k seems about right. Or, wait until the pot gets to 500 btc, then announce a draw in 150 blocks (can still bet until 6 blocks)

again, great work.

[nelisky]

Another possible lotto variant is a pick-3 or pick-4 or whatever, where you require 100% match, but have a drawing for each bitcoin block.  Jackpot keeps growing, and all tickets remain valid, until a winner emerges.

Somewhat like "sudden death overtime" in sport, where you keep playing until someone scores.

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.