# A reverse auction **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 8, 2021, 2:13am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585 "2021-04-08T02:13:22Z")\ **Posts on this page:** 20\ **Page:** 5
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [April 13, 2021, 3:05pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/82 "2021-04-13T15:05:56Z")
> [@Dead\_Cat](#): > > Thanks - somehow I missed post #66, which amusingly was a duplicate bid for post #65 Its reign was brief but eventful. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [April 13, 2021, 3:42pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/83 "2021-04-13T15:42:51Z")
> [@RivkahChaya](#): > > I read an article once that was basically “There’re no ways to improve your odds of winning, other than buying lots and lots of tickets, but there are ways to maximize your payout if you do win,” and it discussed the strategy of picking numbers over 31. It also suggested playing right after a big payout, because almost no one plays the week after a big payout It doesn’t make any sense to play the week after a big payout. You have a better chance of an undivided pot the week after a big payout but the jackpot is so much smaller, the expected value of a ticket is lower than sharing the bigger jackpot the week before. Wikipedia has a list of the largest lottery jackpots in [U.S. history](https://en.wikipedia.org/wiki/Lottery_jackpot_records). The smallest valued winning ticket ($48.6 million cash value) is more than the biggest minimum jackpot that would usually be the prize the week after a big payout. (The current Powerball minimum is $20 million. It had been as high as $40 million. There is no minimum Mega Millions jackpot although I think it also used to be $40 million.) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [April 13, 2021, 11:41pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/84 "2021-04-13T23:41:31Z")
Sadly yes. It will be interesting to see what prediction of group behaviors will be least poor … ---
**Author:** ![EyePaintFaces](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eyepaintfaces/32/7538_2.png) [@EyePaintFaces](https://boards.straightdope.com/u/EyePaintFaces)\ **Post date:** [April 14, 2021, 4:19am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/85 "2021-04-14T04:19:57Z")
not sure if I had thanked you yet for your warm welcome and helpful tips but I greatly appreciate it and thank you for kind words and reassurance ---
**Author:** ![Half\_Man\_Half\_Wit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/half_man_half_wit/32/21766_2.png) [@Half\_Man\_Half\_Wit](https://boards.straightdope.com/u/Half_Man_Half_Wit)\ **Post date:** [April 14, 2021, 5:28am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/86 "2021-04-14T05:28:14Z")
Not sure I’m doing this right, but 34. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [April 21, 2021, 2:33am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/88 "2021-04-21T02:33:00Z")
I’m still curious about what I spoilered in my post #54. (see spoiler below) ISTM that the outcome of this experiment can be manipulated by an entrant attracting or dissuading other Dopers to visit and participate in this thread. It’ll be interesting to watch for that. Especially, considering which entrants might have the biggest opportunity to gain that way. Probably a good thing there is nothing of value at stake here. I would still like to discuss this. Does anyone think there’s any reason why I shouldn’t unspoiler it?\* \*so I can openly talk about it ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [April 21, 2021, 2:49am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/89 "2021-04-21T02:49:12Z")
> [@I\_Love\_Me\_Vol.I](#): > > I would still like to discuss this. Does anyone think there’s any reason why I shouldn’t unspoiler it? I personally don’t feel it would be a problem. Is there anyone who objects? ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [April 21, 2021, 3:33am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/90 "2021-04-21T03:33:24Z")
I think the real participation and hence the fun has mostly worn off, so I for one don’t object to exploring @I_Love_Me_Vol.I’s ideas. Although I don’t see what thesis they hope to present unless its simply that in some vague sense the more contestants the more likely the winning number is bigger. Clearly in a real game/auction like this everyone’s bid would be secret, which precludes someone noticing that right now they’re the winner then trying hard to get the contest closed ASAP or at least to prevent anyone else from entering. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [April 21, 2021, 4:06am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/91 "2021-04-21T04:06:51Z")
> [@LSLGuy](#): > > I think the real participation and hence the fun has mostly worn off, so I for one don’t object to exploring @I_Love_Me_Vol.I’s ideas. > > Although I don’t see what thesis they hope to present unless its simply that in some vague sense the more contestants the more likely the winning number is bigger. You make some good points. I have zero time to discuss this at the moment; I’m posting only to post the unspoilered content in question. If both OP **Little Nemo** and **LSLGuy** are cool with I figure we have a quorum and pass the motion. Here’s the stuff in question unspoilered: > ISTM that the outcome of this experiment can be manipulated by an entrant attracting or dissuading other Dopers to visit and participate in this thread. > It’ll be interesting to watch for that. Especially, considering which entrants might have the biggest opportunity to gain that way. Probably a good thing there is nothing of value at stake here. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [April 21, 2021, 5:21am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/92 "2021-04-21T05:21:29Z")
I don’t see this as an easy contest to manipulate. You could work on attracting more people to join and submit bids by beating the drum for this thread. But doing so would just diminish the chances for those who have already bid. So those of us who have bid have no incentive to seek more bids (assuming we treat this as an exercise in seeking to “win” - as an intellectual exercise in studying how a crowd behaves the more data, the better). So theoretically those of use who have bid should be trying to dissuade other potential bidders; the fewer bids, the less competition we face. But as a practical matter, how do you dissuade people from participating in a purely hypothetical game where there’s no cost to play? Simply by telling people about this thread, you’re risking a Streisand effect. ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [April 21, 2021, 8:47am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/93 "2021-04-21T08:47:10Z")
> [@Little\_Nemo](#): > > So theoretically those of use who have bid should be trying to dissuade other potential bidders I disagree with this. As per the current game state, I have no chance of winning. It is therefore always in my interests to attract more bidders, in the hope they might duplicate the lower bids than mine. If they happen to duplicate my bid first, well, I was never going to win anyway. So there is no downside. ---
**Author:** ![I\_Love\_Me\_Vol.I](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/i_love_me_vol.i/32/521_2.png) [@I\_Love\_Me\_Vol.I](https://boards.straightdope.com/u/I_Love_Me_Vol.I)\ **Post date:** [April 21, 2021, 9:38am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/94 "2021-04-21T09:38:09Z")
> [@Little\_Nemo](#): > > I don’t see this as an easy contest to manipulate. You could work on attracting more people to join and submit bids by beating the drum for this thread. **But doing so would just diminish the chances for those who have already bid.** So those of us who have bid have no incentive to seek more bids [Bolding mine] That depends on what number they bid. For some it would decrease their chances, for others it would increase their chances. As the number of participants grows the optimal bidding strategy changes (under the rules set forth in this thread) ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [April 21, 2021, 11:46am UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/95 "2021-04-21T11:46:06Z")
Indeed - apologies if this has already been stated, but fairly obviously, any bid higher than the number of posts in the thread is very unlikely to be the winner (I thought it was impossible at first, but not so - if everyone anticipates a high number of posters and bids high themselves). I probably didn’t give enough consideration to this factor when making my own bid - clearly you have to anticipate how many bids there will eventually be, I just picked what I thought was the lowest number that no-one else was likely to pick. But the assessment of that likelihood is heavily dependent on the number of bidders. As it is, as I subsequently stated, I think the winning bid is very likely to be in the single digits. Looked at from the other direction, we could consider the optimum bid where the number of bidders is known - but that seems to lead to a sort of prisoner’s dilemma. For example, with 2 bidders you clearly have to bid 1. With 3 bidders, you could consider bidding 2 (hoping to win if both the other bidders bid 1). But I suspect bidding 1 might still be best. It quickly gets more complicated from there on. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [April 21, 2021, 1:20pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/96 "2021-04-21T13:20:39Z")
> [@Little\_Nemo](#): > > I don’t see this as an easy contest to manipulate. You could work on attracting more people to join and submit bids by beating the drum for this thread. But doing so would just diminish the chances for those who have already bid. So those of us who have bid have no incentive to seek more bids (assuming we treat this as an exercise in seeking to “win” - as an intellectual exercise in studying how a crowd behaves the more data, the better). > > So theoretically those of use who have bid should be trying to dissuade other potential bidders; the fewer bids, the less competition we face. But as a practical matter, how do you dissuade people from participating in a purely hypothetical game where there’s no cost to play? Simply by telling people about this thread, you’re risking a Streisand effect. If we assume everyone is playing fairly, they bid before they look at the other bidders’ numbers but then they are free to check on where they stand. If you have a unique bid but not the lowest unique bid, you might guess that more bidders are more likely to eliminate teh higher ranked competition than yourself. It might not work precisely. Maybe the bidders you attract don’t manage to bid all the lower numbers but if your cajoling were even more blatant (by saying for example, “It looks like a single digit will win!”) you could influence the numbers that the new entrants guess and improve your own odds of winning even further. ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [April 21, 2021, 3:33pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/97 "2021-04-21T15:33:46Z")
> [@Tired\_and\_Cranky](#): > > if your cajoling were even more blatant (by saying for example, “It looks like a single digit will win!”) Heh - I did wonder whether I should have spoilered that (and if this was a subtle dig in my direction, fair comment and no offence taken!) - I just figured we’re so deep in the thread by now it made little difference either way. I really don’t care if I ‘win’, anyway. ---
**Author:** ![Tired\_and\_Cranky](https://avatars.discourse-cdn.com/v4/letter/t/a87d85/32.png) [@Tired\_and\_Cranky](https://boards.straightdope.com/u/Tired_and_Cranky)\ **Post date:** [April 21, 2021, 4:11pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/98 "2021-04-21T16:11:55Z")
I’m sorry! I didn’t mean to call anyone out in particular. I was just imagining a hypothetical where someone was trying to manipulate the participation and an easy-to-understand example. I don’t consciously remember reading your post. Thanks for not taking offense because none was intended. ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [April 21, 2021, 4:27pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/99 "2021-04-21T16:27:55Z")
**17** It’s the smallest arbitrary number. 😉 ---
**Author:** ![Dead\_Cat](https://avatars.discourse-cdn.com/v4/letter/d/9fc29f/32.png) [@Dead\_Cat](https://boards.straightdope.com/u/Dead_Cat)\ **Post date:** [April 21, 2021, 5:32pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/100 "2021-04-21T17:32:57Z")
It’s really no problem at all, absolutely no apology needed. > [@Pleonast](#): > > **17** > It’s the smallest arbitrary number. Interestingly, I nearly bid that, but then decided (a bit like Douglas Adams deciding on ‘42’) that I didn’t want a prime number, or even an odd number - instead I chose a dull even number that I thought no-one else would pick. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [May 7, 2021, 8:55pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/101 "2021-05-07T20:55:30Z")
Bumping this for anyone who wants to get a bid in. ---
**Author:** ![CardboardBoxx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cardboardboxx/32/7079_2.png) [@CardboardBoxx](https://boards.straightdope.com/u/CardboardBoxx)\ **Post date:** [May 7, 2021, 9:03pm UTC](https://boards.straightdope.com/t/a-reverse-auction/939585/102 "2021-05-07T21:03:48Z")
> **My Bid** > > 5 [Previous page](https://boards.straightdope.com/t/a-reverse-auction/939585.md?page=4) [Next page](https://boards.straightdope.com/t/a-reverse-auction/939585.md?page=6)