Welcome, Guest
Username: Password: Remember me

TOPIC: Applying bids to multi-item auctions

Applying bids to multi-item auctions 1 year 7 months ago #13

Matthew Hayward wrote:

David Zych wrote: Forking a new thread from
truedungeon.com/forum?view=topic&defaultmenu=141&catid=584&id=250328&start=48#353987
I agree with Wade, and I'll try to fill in the details of why.

Imagine a very faithful, very patient virtual assistant to whom you have given the instructions "Try to win 17 PYPs at the lowest price you can. Don't pay more than $105 each." This assistant uses that information to place actual bids for individual items on your behalf, one at a time. Every bidder has such an assistant, and the assistants do not share knowledge with each other.

In my opinion, the appropriate auction result is the one that is consistent with this model. Of course there are implementation shortcuts available, but to see how the model works, let's walk through all the actual bids which result deterministically from the application of B's bid.

Initially A bids $0.25 on PYP#1-17:

PYP#1-17 A $0.25
PYP#18-32 $0

1. B bids $0.25 on PYP#18-32.

PYP#1-17 A $0.25
PYP#18-32 B $0.25

...snip...


Here is what I think you're doing, is equivalent to can you tell me if it amounts to the same thing?

1. Take all the bid amounts and quantities, and at the end of the bidding period:

2. Run a virtual auction for each identical item sequentially, one at a time, using eBay rules, removing the winning bids from the bid pool at the start of the subsequent auction.


That's definitely not what I'm doing. I am running all 32 auctions at the same time, so that each virtual assistant can place its next actual bid on whichever item happens to be going for cheapest at that moment. None of the auctions is over until all virtual assistants have stopped bidding.

If so, consider what happens in this scenario:

There are 2 identical items available.

A bids first and wants 1 item at $105 or less
B bids second and wants 1 item at $100 or less
C bids third wants 1 item at $1 or less


Great example! Much easier to follow than 32 items.

Here's the step by step breakdown at Auction House Lambda:
1. A bids $0.25 on item 1. A is happy.
2. B bids $0.25 on item 2. B is happy.
At this point A and B are winning one item each for $0.25
3. C bids $0.50 on item 1 (outbidding A).
4. A bids $0.25 on item 2 (displacing B, since early bids win ties).
5. B bids $0.50 on item 2 (outbidding A).
6. A bids $0.50 on item 1 (displacing C, since early bids win ties).
At this point A and B are winning one item each for $0.50
7. C bids $0.75 on item 1 (outbidding A).
8. A bids $0.50 on item 2 (displacing B, since early bids win ties).
9. B bids $0.75 on item 2 (outbidding A).
10. A bids $0.75 on item 1 (displacing C, since early bids win ties).
At this point A and B are winning one item each for $0.75
11. C bids $1 on item 1 (outbidding A).
12. A bids $0.75 on item 2 (displacing B, since early bids win ties).
13. B bids $1 on item 2 (outbidding A).
14. A bids $1 on item 1 (displacing C, since early bids win ties).
At this point A and B are winning one item each for $1.
15. C gives up. A and B win for $1 each.

Hopefully this helps you see my conceptual model. You'll notice that in this simple case, Auction House Lambda and Auction House Beta end up with the same answer.

Now suppose D wants one item at $110. At Auction House Lambda, D will bid both A and B up to $100, one increment at a time (just like C did), then bid $105 on item 1 (outbidding A). A bids $100 on item 2 (displacing B ), and B gives up.

Result: D wins for $105 and A wins for $100.

Auction House Beta would knock D's price down to $100 as well. That's good news (at least in the short term) if you're D. But I see three comparative downsides:

First, if I'm B, this result doesn't sit quite right. Shouldn't somebody who bids after me need to actually pay more than I was willing to pay in order to win the item I wanted? That's not a deal-breaker as long as the rules were stated clearly up front, but IMO it's a consideration.

Second, Auction House Beta ends up taking in $5 less. Running an auction house is hard work! If there are two generally reasonable sets of rules to choose from, I certainly won't begrudge the auction house choosing the one that nets them a little bit more in the end. I'm grateful there are auction houses available so I don't have to pay $250 for my PYPs.

Third, Auction House Beta offers less incentive for early bidding compared to Auction House Lambda. Early bidding helps auctions to succeed, and we all (bidders and auction house managers alike) want TD auctions to succeed.
dmrzzz's trade thread

Yes, my AC is lower than the Wizard's. No regrets!

Please Log in or Create an account to join the conversation.

Applying bids to multi-item auctions 1 year 7 months ago #14

Matthew Hayward wrote:

Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


Using your system, if I am B, I'm not very happy and am confused as to why I am not winning two of the items I bid on when my max was $100 and that A schmuck is winning 2 of them for $1.

Using the other system (which was the system I used when I ran my auction) it would be abundantly clear to me that A bid first and had a higher maximum than I did, because all the bids would be at my maximum, but I would only be winning one of them.

Your system seems to assume that you have all the bids at once, and do the calculations after you have the bids, with no updating I guess?

Correct me if I'm wrong, but would your system keep A and B winning for $1 until someone randomly outibid their maximums? How would someone know what their maximums were to outbid them? It seems highly flawed.

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

You are telling me your post says:

item 1: A @ $1
item 2: A @ $1
item 3: B @ $1

So how do those ever go up without someone guessing A and B's max bids? If B's bid of $100 didn't raise them, how will they ever increase?

What if random guy D comes along and says "oh nice! those are only $1 each, I'll bid $5"

Does his $5 bid increase their prices to $5? And if so, why didn't B's increase the prices? Does B need to send you a separate bid now for another one (because he wanted 2 of them) in order to raise the price? Does he have to guess a higher number than his original $100 the first time around?


Your system seems to be a completely blind system where people put in their maximums, and at the end the chips simply fall where they fall.

The auctions being run currently are updated regularly so people can see where they stand, and make adjustments and decisions. As a buyer, that is definitely the system I prefer.

Please Log in or Create an account to join the conversation.

Applying bids to multi-item auctions 1 year 7 months ago #15

It comes.to whether you prioritize the person's request on number of items or their (assumed) desire to pay the lowest price, regardless of how many items they say they want.
First ever death in True Horde
"Well, with you guarding 2 players, that means you take 90. Are you dead?"
-Incognito

My token shop/trade thread: Wade's Wide World of Wonder 

My Current Paladin Build 

Please Log in or Create an account to join the conversation.

Applying bids to multi-item auctions 1 year 7 months ago #16

Matthew Hayward wrote: Here is one thing I would want my auctioneer to guarantee me:

1. The price I pay in no way depends on my max bid - it only depends on what other people's max bids are. (Of course the number of items I win can depend on my max bid).


At Auction House Lambda, your price only depends on your max bid in the case where your max bid is both a winning and a losing bid.

If you bid $x each on 17 PYPs and you win all 17, then either you're paying $x because you had to in order to outbid someone else, or you're paying less than $x because you successfully outbid everyone for less.

If you win fewer than 17 of them, you're definitely paying $x, because the only way you can win fewer than 17 is because somebody else successfully outbid you for some of them (and they won't bother to outbid you on an $x one while there's one still going for less than $x).

2. No one who bid less than me will receive an identical item to me at a lesser price.


At Auction House Lambda, no one who bid after you will receive an identical item to you at a lesser price. Some people who bid earlier than you might get an identical item for one bid increment less.

(or some people who bid after you might pay one bid increment more than you -- but never both at once)

This is important because my time is valuable


Here we agree 100%, and Auction House Lambda has you covered; once you've decided on your max bid(s) it is absolutely to your advantage to submit them as early as possible.

I also think it's important that very few people, if any, would actually rather have 17 PyPs at $105 each than 16 at $80. With the difference in cost they could buy a $250 pack from TD, get their 17th PyP, and have money to burn left over. So you should tell your minions to like, be more smart and not take you so literally ;).


You don't know in advance that those are the possible outcomes! So the going price is $80 right now and you're winning 16? Maybe you'll get all 17 at $85. Or at $90. Your minion doesn't know what will happen until it puts in an actual bid and sees whether the other people's minions keep bidding or not -- just like a live auction in person (or rather, just like 32 simultaneous live auctions in neighboring rooms).

It's on you to give your minion a set of instructions that prioritizes the outcomes you prefer. If you don't want your minion to keep trying to get you a 17th PYP once the price gets past $80, then bid it that way: 16 PYPs at max $100 and 1 more PYP at max $80. Or whatever you like. Make it a sliding scale: bid 1 at max $130, 1 at max $125, 1 at max $120, 1 at max $115, 1 at max $110, and so on. (NB: of course auctioneers are people, and if you make it too obnoxious then they might just throw you out. But the algorithm handles this input just fine.)

But also, those are never going to be the possible outcomes in a real auction. If PYPs are currently going for $80 and $85, then someone else who hasn't bid yet is going to come along and bid them up to a more reasonable price. And if for some reason they don't, the whole auction will fail anyway and nobody will get any PYPs (the mere thought brings tears to my eyes).
dmrzzz's trade thread

Yes, my AC is lower than the Wizard's. No regrets!

Please Log in or Create an account to join the conversation.

Applying bids to multi-item auctions 1 year 7 months ago #17

Wade Schwendemann wrote:

Matthew Hayward wrote:

Wade Schwendemann wrote: I dont know about the system that was proposed above, but my system is
A bids on item, takes the lead at 0.25
B is on item, takes the lead at 0.25
C bids on item, but at a max of $1

Since they bid first, A and B take the lead at $1 each, as they bid before C.

Basically, all winning bids are within one bid increment of one another.

If someone bids before you and has a lower max bid than you, they are the first ones to lose their items when your higher bid comes in.

If you want 10, and they want 5 of an item there are 12 of, shouldnt you have to pay more for the privilege of getting the number of items you want, and doing so later?

If you bid first with the higher max bid, you only pay their max bid for your items and get the number you want.

I'm not sure if I'm saying something very similar or something very different from what you're after. I am planning to try to figure out the difference between the final numbers for my recent auction using the method I described and what they would have been had I used your method.

I cannot guarantee I will get this done, but I am planning to try.



Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


You are correct.

S1
A gets the 2 items they want, and pays $100
B gets 1 of the 2, and pays $100
C gets nothing

S2
A gets 2 items for $1
B gets 1 item for $1
C gets nothing

I believe that, while the result is the same with your method between the 2, the difference lies in the desires of the bidders.

Their desires need to be respected and accounted for in some way.


I agree completely!

Can you explain any desire bidder A, or bidder B might have that is better handled with your approach than mine?

My approach has the large advantage that the prices A and B pay will always be less than or equal to your approach.

Under both of our approaches both bidders will always receive the same number of tokens.

I can't think of what other desires A and B might have that are relevant.

But I would be interested to hear of one you might identify.

Please Log in or Create an account to join the conversation.

Last edit: by Matthew Hayward.

Applying bids to multi-item auctions 1 year 7 months ago #18

Lequinian wrote:

Matthew Hayward wrote: Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


In S1, I believe A has 2 @ $100 and B has 1 @ $100.

In your method maybe, not in mine. In mine the winning bid amount is set by the first bid to not win anything. B's bid of 2@100 has won something, so it is C's bid of 1@1 which is the first bid to not win anything.

How does your approach allow B to be happy about not getting his 2nd item in scenario 1?


B doesn't get a second item in any scenario, under any of the proposed auction methods. So there is nothing for me to explain here with regard B that everyone else doesn't also need to explain.

The short answer to B, should they complain, would be: "Other bidders who bid more than you won more tokens." Why would B be upset that they won fewer tokens than someone else who bid more than them - that's just how auctions work?

Please Log in or Create an account to join the conversation.

Last edit: by Matthew Hayward.

Applying bids to multi-item auctions 1 year 7 months ago #19

Wade Schwendemann wrote:

Lequinian wrote:

Matthew Hayward wrote: Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


In S1, I believe A has 2 @ $100 and B has 1 @ $100. How does your approach allow B to be happy about not getting his 2nd item in scenario 1?


Probably because he only has to pay $1 for the one he does get!

It's a different way of looking at it.

I'm enjoying this exercise, but it definitely does show different priorities.

In this example, were I B, I might wonder why I didnt get 2 items. If the bid were at my max, I would know that I lost because A bid first without having to ask.


Here is how A and B would see things as the auction went on (Scenario 1 above):

After A's Bid:

Item-1 : A - $0
Item-2 : A - $0

After B's Bid:

Item-1 : A-$0
Item-2 : A-$0
Item-3 : B-$0

Right now, B knows that A's bid is higher than theirs (or it is the same and A bid earlier), and that if they want to get 2 items, they need to increase their bid. A and B both know they are the only bidders (Because the price is still $0).

After C's Bid:

Item-1 : A-$1
Item-2 : A-$1
Item-3 : B-$1


All B has to do to get 2 items is increase their bid. But if they bid their max bid right off the bat, they can go to best rest assured that A has bid more - and that there is no reason to be upset about winning less items than someone else who bid more.

Please Log in or Create an account to join the conversation.

Last edit: by Matthew Hayward.

Applying bids to multi-item auctions 1 year 7 months ago #20

kurtreznor wrote:

Wade Schwendemann wrote:

Matthew Hayward wrote:

Wade Schwendemann wrote: I dont know about the system that was proposed above, but my system is
A bids on item, takes the lead at 0.25
B is on item, takes the lead at 0.25
C bids on item, but at a max of $1

Since they bid first, A and B take the lead at $1 each, as they bid before C.

Basically, all winning bids are within one bid increment of one another.

If someone bids before you and has a lower max bid than you, they are the first ones to lose their items when your higher bid comes in.

If you want 10, and they want 5 of an item there are 12 of, shouldnt you have to pay more for the privilege of getting the number of items you want, and doing so later?

If you bid first with the higher max bid, you only pay their max bid for your items and get the number you want.

I'm not sure if I'm saying something very similar or something very different from what you're after. I am planning to try to figure out the difference between the final numbers for my recent auction using the method I described and what they would have been had I used your method.

I cannot guarantee I will get this done, but I am planning to try.



Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


You are correct.

S1
A gets the 2 items they want, and pays $100
B gets 1 of the 2, and pays $100
C gets nothing

S2
A gets 2 items for $1
B gets 1 item for $1
C gets nothing

I believe that, while the result is the same with your method between the 2, the difference lies in the desires of the bidders.

Their desires need to be respected and accounted for in some way.


Hold on, i think i missed something. What method has S1 result in A getting two, B getting one, and all 3 sell for $1? Because that should be right out. If i am B, i would call bullshit. I wanted a 2nd item, and i bid more than the $1 selling price.


After you called bullshit, I'd explain to you that A bid more than you, and this is an auction, and ask why you're upset that someone who bid more than you in an auction won more items than you.

Then I would invite you to explain to me any way of running an auction whatsoever with these facts:

3 identical items:
A has bid 2 at $105
B has bid 2 at $100
C has bid 1 at $1

Where you get a better outcome as B than what I've proposed above, and to which both A and C would agree is fair also. (You should want A and C to agree it's fair too, because you could just as easily be A or C one day).

Can you do that? Is there any possible better outcome for B in this scenario than 1 token at $1 no matter how you run it?

If there is, I don't see it.

Please Log in or Create an account to join the conversation.

Last edit: by Matthew Hayward.

Applying bids to multi-item auctions 1 year 7 months ago #21

Matthew Hayward wrote:

Wade Schwendemann wrote:

Lequinian wrote:

Matthew Hayward wrote: Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


In S1, I believe A has 2 @ $100 and B has 1 @ $100. How does your approach allow B to be happy about not getting his 2nd item in scenario 1?


Probably because he only has to pay $1 for the one he does get!

It's a different way of looking at it.

I'm enjoying this exercise, but it definitely does show different priorities.

In this example, were I B, I might wonder why I didnt get 2 items. If the bid were at my max, I would know that I lost because A bid first without having to ask.


Here is how A and B would see things as the auction went on (Scenario 1 above):

After A's Bid:

Item-1 : A - $0
Item-2 : A - $0

After B's Bid:

Item-1 : A-$0
Item-2 : A-$0
Item-3 : B-$0

Right now, B knows that A's bid is higher than theirs (or it is the same and A bid earlier), and that if they want to get 2 items, they need to increase their bid. A and B both know they are the only bidders (Because the price is still $0).

After C's Bid:

Item-1 : A-$1
Item-2 : A-$1
Item-3 : B-$1


All B has to do to get 2 items is increase their bid. But if they bid their max bid right off the bat, they can go to best rest assured that A has bid more - and that there is no reason to be upset about winning less items than someone else who bid more.


I would never participate in an auction run this way. I would not have confidence in the person running it.

I would post what the freak on not winning an item that I significantly bid higher than the winning bid.

Please Log in or Create an account to join the conversation.

Applying bids to multi-item auctions 1 year 7 months ago #22

edwin wrote:

Matthew Hayward wrote:

Wade Schwendemann wrote:

Lequinian wrote:

Matthew Hayward wrote: Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


In S1, I believe A has 2 @ $100 and B has 1 @ $100. How does your approach allow B to be happy about not getting his 2nd item in scenario 1?


Probably because he only has to pay $1 for the one he does get!

It's a different way of looking at it.

I'm enjoying this exercise, but it definitely does show different priorities.

In this example, were I B, I might wonder why I didnt get 2 items. If the bid were at my max, I would know that I lost because A bid first without having to ask.


Here is how A and B would see things as the auction went on (Scenario 1 above):

After A's Bid:

Item-1 : A - $0
Item-2 : A - $0

After B's Bid:

Item-1 : A-$0
Item-2 : A-$0
Item-3 : B-$0

Right now, B knows that A's bid is higher than theirs (or it is the same and A bid earlier), and that if they want to get 2 items, they need to increase their bid. A and B both know they are the only bidders (Because the price is still $0).

After C's Bid:

Item-1 : A-$1
Item-2 : A-$1
Item-3 : B-$1


All B has to do to get 2 items is increase their bid. But if they bid their max bid right off the bat, they can go to best rest assured that A has bid more - and that there is no reason to be upset about winning less items than someone else who bid more.


I would never participate in an auction run this way. I would not have confidence in the person running it.

I would post what the freak on not winning an item that I significantly bid higher than the winning bid.


Would you feel the same if all through the bidding you could see that you were not at the top of the list, and therefore knew there were others who had bid more?

I would also ask you to seriously consider this scenario:

Here is the scenario:

3 identical items:

A bids 2 at $105
Edwin bids 2 at $100
C bids 1 at $1

Can you provide any outcome for Edwin which is better than winning 1 token at $1 with any auction system you like?

Can you provide any reason to mistrust the person running this auction, but not mistrust someone else who charges you a few bucks under your max bid, and you just have to take on faith that there was another bidder back there behind you?

It's OK if you don't like this style of auction which, again, I did not invent, and is a common way of running multi-item auctions, and which provably has the same outcome in terms of who wins how many, and is guaranteed to charge each and every winning bidder less than or equal to the winning bid in the other systems provided so far.

It is really incredible to me the amount of pushback "pay less for your tokens" is getting on this thread. I'm in the wrong business, clearly.

Please Log in or Create an account to join the conversation.

Last edit: by Matthew Hayward.

Applying bids to multi-item auctions 1 year 7 months ago #23

Matthew Hayward wrote:

edwin wrote:

Matthew Hayward wrote:

Wade Schwendemann wrote:

Lequinian wrote:

Matthew Hayward wrote: Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


In S1, I believe A has 2 @ $100 and B has 1 @ $100. How does your approach allow B to be happy about not getting his 2nd item in scenario 1?


Probably because he only has to pay $1 for the one he does get!

It's a different way of looking at it.

I'm enjoying this exercise, but it definitely does show different priorities.

In this example, were I B, I might wonder why I didnt get 2 items. If the bid were at my max, I would know that I lost because A bid first without having to ask.


Here is how A and B would see things as the auction went on (Scenario 1 above):

After A's Bid:

Item-1 : A - $0
Item-2 : A - $0

After B's Bid:

Item-1 : A-$0
Item-2 : A-$0
Item-3 : B-$0

Right now, B knows that A's bid is higher than theirs (or it is the same and A bid earlier), and that if they want to get 2 items, they need to increase their bid. A and B both know they are the only bidders (Because the price is still $0).

After C's Bid:

Item-1 : A-$1
Item-2 : A-$1
Item-3 : B-$1


All B has to do to get 2 items is increase their bid. But if they bid their max bid right off the bat, they can go to best rest assured that A has bid more - and that there is no reason to be upset about winning less items than someone else who bid more.


I would never participate in an auction run this way. I would not have confidence in the person running it.

I would post what the freak on not winning an item that I significantly bid higher than the winning bid.


Would you feel the same if all through the bidding you could see that you were not at the top of the list, and therefore knew there were others who had bid more?

I would also ask you to seriously consider this scenario:

Here is the scenario:

3 identical items:

A bids 2 at $105
Edwin bids 2 at $100
C bids 1 at $1

Can you provide any outcome for Edwin which is better than winning 1 token at $1 with any auction system you like?

Can you provide any reason to mistrust the person running this auction, but not mistrust someone else who charges you a few bucks under your max bid, and you just have to take on faith that there was another bidder back there behind you?

It's OK if you don't like this style of auction which, again, I did not invent, and is a common way of running multi-item auctions, and which provably has the same outcome in terms of who wins how many, and is guaranteed to charge each and every winning bidder less than or equal to the winning bid in the other systems provided so far.

It is really incredible to me the amount of pushback "pay less for your tokens" is getting on this thread. I'm in the wrong business, clearly.


I would expect to win one item at $1 and one item at $1+bid increment since that is in alignment with my bid. And a better deal for the bidder. It is all on you to satisfy A not getting two items and is not my issue.

Please Log in or Create an account to join the conversation.

Last edit: by edwin.

Applying bids to multi-item auctions 1 year 7 months ago #24

jpotter wrote:

Matthew Hayward wrote:

Hmm. What do you do in this scenario:

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

And this one:

S2
3 identical items
A wants 2 at $105
B wants 1 at $100
C wants 1 at $1

In both scenarios my approach gives A two items, B one item, and both A and B pay $1.

I suspect deviating from my approach gives a large difference in the cost someone pays between S1 and S2.

I suspect this deviation would cause bidders to prefer my approach.


Using your system, if I am B, I'm not very happy and am confused as to why I am not winning two of the items I bid on when my max was $100 and that A schmuck is winning 2 of them for $1.

Using the other system (which was the system I used when I ran my auction) it would be abundantly clear to me that A bid first and had a higher maximum than I did, because all the bids would be at my maximum, but I would only be winning one of them.

Your system seems to assume that you have all the bids at once, and do the calculations after you have the bids, with no updating I guess?


Not at all! You'd continuously update with each new bid - I showed an example earlier of how this would work as bids come in.

Every time a bid comes in, you run the procedure:

1. Sort the bids from highest to lowest.
2. Allocate items to the highest bidders in order.
3. Set the price based on the first bid to not win anything.


Correct me if I'm wrong, but would your system keep A and B winning for $1 until someone randomly outibid their maximums? How would someone know what their maximums were to outbid them? It seems highly flawed.


Not exactly - A and B would keep winning until someone outbid them (because it's an auction :P) - but the price would keep rising as more and more bids came in between $1 and their bids.

The price is set by the highest bid which isn't winning anything - which is just a straightforward generalization of eBay bidding to multiple items - where the price is also set by the highest bid which isn't winning anything.

S1
3 identical items
A wants 2 at $105
B wants 2 at $100
C wants 1 at $1

You are telling me your post says:

item 1: A @ $1
item 2: A @ $1
item 3: B @ $1

So how do those ever go up without someone guessing A and B's max bids? If B's bid of $100 didn't raise them, how will they ever increase?

What if random guy D comes along and says "oh nice! those are only $1 each, I'll bid $5"


Let's assume D bids $5 on all 3. Then the bids are:

A: 2 @ $105
B: 2 @ $100
D: 3 @ $5
C: 1 @ $1

The we award items to those who bid the most (because it's an auction :P):

A is the highest bidder and gets 2 (all they asked for).
B is the second highest bidder and gets 1 (which is all that is left).

Now the price is set by the next bid that didn't win anything, which is D's bid at $5. A and B both pay $5 each for their tokens.

Does his $5 bid increase their prices to $5?

Exactly right.

And if so, why didn't B's increase the prices?


Because B's bid was partially winning something.

You _could_ run this system as setting the sale price to the bid amount of the first bid with unsatisfied quantity, which would be B's bid of 2@100 which is not getting fully fulfilled. I think it is more bidder friendly to go down to the next bid.

Ask yourself, if you were B, which rule would you want?
* The one that gives A two at $2, and you one at $1
* The one that gives A two at $100, and you one at $100
?

Does B need to send you a separate bid now for another one (because he wanted 2 of them) in order to raise the price?

B never wants to raise the price! B wants to win more tokens at a low price! If B wants to raise the price they can send the auctioneer money for no reason :P.

But I get what you mean.

B could up their bid say from two at $100 to one at $120, and one at $100. Then the bids would be:

B: 1 at $120
A: 2 at $105
B: 1 at $100
C: 1 at $1

The prices listed would then be:

Item1 : B - $1
Item2 : A - $1
Item3 : A - $1

B would then have learned that A's bit most be less than $120 *because B is leading on item 1), but more than $100 (because A is still getting 2 slots before B's $100 bid).

Does he have to guess a higher number than his original $100 the first time around?

I don't know what you mean by guess - these are bids. If other bids come in, B will have to pay up to this amount.

Your system seems to be a completely blind system where people put in their maximums, and at the end the chips simply fall where they fall.

Do you still feel this way now that there's been some more information above?

The auctions being run currently are updated regularly so people can see where they stand, and make adjustments and decisions. As a buyer, that is definitely the system I prefer.


I hope you can now see that the only difference between the system I'm proposing and yours is that sometimes you'll pay less.

Please Log in or Create an account to join the conversation.

Time to create page: 0.199 seconds