Author Message
juangrande
PostPosted: Sat Jan 24, 2009 9:24 am    Post subject:

Cupid wrote:
That is possibly the most succinct and accurate summary of how and why we use Gixen that we have ever had on here.


That's right, Mark! Now why couldn't we have been than succinct and accurate? :roll: :D
Cupid
PostPosted: Sat Jan 24, 2009 7:30 am    Post subject: Re: Thanks

hosta499 wrote:

To win, there need to be a combination of a high max bid and sniping.


That is possibly the most succinct and accurate summary of how and why we use Gixen that we have ever had on here.

Best of luck with all your future sniping.
hosta499
PostPosted: Sat Jan 24, 2009 5:41 am    Post subject: Thanks

Now it is crystal clear. Thanks, everyone.

To win, there need to be a combination of a high max bid and sniping.
juangrande
PostPosted: Thu Jan 22, 2009 4:59 pm    Post subject:

mario wrote:
o***r's bid is irrelevant, it came before y***a's bid. Your bid was never compared against it.


Mario is right: your bid was only compared to y***a's bid. To make this clearer, this is what the bidding history looked like just prior to Gixen placing your bid:

Code:

y***a    US $41.00 Jan-20-09 17:47:54 PST
o***r    US $40.00 Jan-20-09 17:47:52 PST
a***b    US $35.00 Jan-20-09 16:52:49 PST


Notice that the current bid was at $41.00, one bid increment above the next highest bid of $40.00. This is how eBay's modified Vickrey auctions work.

When you bid, your bid was compared to the current bid ($41.00) and the high bidder's bid (which is hidden). Since your bid was at least one bid increment more than the current bid (i.e., at least $42.00), it was accepted. Since it was less than the (hidden) high bid, the high bidder won for one bid increment more than your bid (i.e., $51.57). We have no way of knowing how much higher the high bid was: it could have been $100 and the high bidder would still have won for $51.57 as indicated by the final bid history you gave us (and repeated below).

Code:

y***a    US $51.57 Jan-20-09 17:47:54 PST
hosta499 US $50.57 Jan-20-09 17:47:58 PST
o***r    US $40.00 Jan-20-09 17:47:52 PST
a***b    US $35.00 Jan-20-09 16:52:49 PST
mario
PostPosted: Thu Jan 22, 2009 1:31 pm    Post subject:

hosta499,

o***r's bid is irrelevant, it came before y***a's bid. Your bid was never compared against it.
hosta499
PostPosted: Thu Jan 22, 2009 1:18 pm    Post subject: One more time

Thanks all for the explanations. It is now becoming clear. To be sure, here is the actual data from my auction: the ending time and the last four entries in history.

Ended: Jan 20, 2009, 05:48:03 PM PST

y***a US $51.57 Jan-20-09 17:47:54 PST
hosta499 US $50.57 Jan-20-09 17:47:58 PST
o***r US $40.00 Jan-20-09 17:47:52 PST
a***b US $35.00 Jan-20-09 16:52:49 PST

eSnipe placed my (hosta499's) max bid at 17:47:58, and y***a outbid me by $1 increment at 17:47:54. This was purplexing to me, but your explanations have clarified it. So far, so good.

Now look at o***r's bid of $40.00 at 17:47:52. The difference between his and mine is ~$10, and way over the $1 increment. Shouldn't eSnipe place my bid at the $1 increment instead? Or, are there other bids at $1 increments going on between 17:47:52 and 17:47:58 that are not reported in history, forcing eSnipe to eventually place my max bid?

I've been an eBayer for over five years, and this is the first time I come across such a scenario.
juangrande
PostPosted: Thu Jan 22, 2009 10:03 am    Post subject:

Vickrey auctions are a better model for eBay auctions than "proxy bidding". A Vickrey auction is a sealed-bid second-price auction. This means that bids are hidden (e.g., sealed in an envelope) from other bidders and when the auction ends, the high bidder wins for the amount of the second-highest bid. The idea is to induce bidders to bid the most they would be willing to pay since they will only pay what the next highest bidder was willing to pay.

If one compares this to eBay auctions, one finds only two significant differences: (1) only the high bidder's bid is sealed (hidden) and only partially so, and (2) the current bid (while the auction is running) and the winning bid (after the auction closes) is higher than the second-highest bid by at most one bid increment.

The point of all this is that there really is no "proxy bidding": eBay simply adjusts the amount of the current winning bid based on the appearance of additional bids. Thus, it is completely accurate to only record the time when the bid was placed. One can easily reconstruct what the winning bids were at previous times from the bid history.

The only reason for calling eBay's system "proxy bidding" is so that it would seem more familiar to the great majority of people who are unfamiliar with auction formats other than the well-known outcry (going, going, gone!) auctions.
Cupid
PostPosted: Thu Jan 22, 2009 6:59 am    Post subject: Re: Sorry and thanks

hosta499 wrote:
- But what about n***j's bid time, 14:49:39? Is that the time n***j placed a bid with a max higher than mine?


Yes

hosta499 wrote:
If so, it would be more accurate for eBay to report the actual winning bid time instead, i.e. after 15:12:10.


You'd have to take that up with eBay, they report the time that the bid was placed not the time that the proxy was used, personally I think eBay is correct to report it the way it does, it imparts more information overall, you can see when the proxy was used by the times of the lower bids.

hosta499 wrote:
- n***j's winning bid is executed by eBay within the final six seconds after my bid is placed. What is the minimal time eBay needs to execuate a final bid? IOW, if I direct eSnipe to place my bid 1, 2, or 3 seconds before the auction ends, can I avoid being out-sniped?


The proxy bidding system effectively takes no time at all, you are outbid as soon as your bid is accepted by eBay. eBay just works out the current auction price from all the accepted bids, it doesn't care when they were accepted. It is impossible to bid faster, no matter what sniping service you use. The highest accepted bid always wins. You are not being outsniped you are being outbid by an earlier bid, its a different thing from a user reacting to the bid that you have placed which is what sniping protects you from, nothing more.
hosta499
PostPosted: Thu Jan 22, 2009 6:37 am    Post subject: Sorry and thanks

Thanks to both of you for your responses.

I signed up with eSnipe before finding out about your site. Will switch once my eSnipe points are used up!

Follow up questions, using the same example:

- Let's assume that the auction ending time is 15:12:16, and I have asked eSnipe to place my bid six seconds prior to it. Hence my bid is placed at 15:12:10.

- But what about n***j's bid time, 14:49:39? Is that the time n***j placed a bid with a max higher than mine? If so, it would be more accurate for eBay to report the actual winning bid time instead, i.e. after 15:12:10.

- n***j's winning bid is executed by eBay within the final six seconds after my bid is placed. What is the minimal time eBay needs to execuate a final bid? IOW, if I direct eSnipe to place my bid 1, 2, or 3 seconds before the auction ends, can I avoid being out-sniped?
mario
PostPosted: Wed Jan 21, 2009 6:31 am    Post subject:

Hey, eSnipe is a competitor! :-)
Nevertheless, it's not eSnipe's fault. Sniping services will not place a bid if the current high bid is higher than your bid; but they will if the current bid is lower, and current high bidder's maximum bid is higher than yours (just not previously shown). This is what happened in the scenario you described.
Cupid
PostPosted: Wed Jan 21, 2009 6:30 am    Post subject:

The way that eBay works with proxy bidding your high bid is invisible to everyone (including all sniping services) until it is outbid by a higher value bid being accepted.

So, as long as the current auction price is lower than your bid by at least one bid increment, then every sniping service should place your bid, it doesn't mean that you will necessarily win though if the high bidders actual bid (placed earlier) is higher than yours, the auction price is just increased by your bid plus up to one increment.
hosat499
PostPosted: Wed Jan 21, 2009 5:56 am    Post subject: Need more clarification

I've been using eSnipe for over a year and have been happy with it, until now. In the past, if an item has a bid higher than my max, eSnipe will not place the bid. But recently I came across a situation like OP's:

n***j US $133.50 Jan-14-09 14:49:39 PST
e***n US $131.00 Jan-14-09 15:12:10 PST

Assume that I'm e***n, note that n***j's winning bid time is EARLIER than mine. Why would eSnipe place my bid if there is already a higher bid? Does n***j has a pending higher bid that is invisible to eSnipe?

Thanks.
Cupid
PostPosted: Thu Jan 15, 2009 1:58 am    Post subject:

I dont see anything unusual to that bid history, the highest bidder placed a bid well before the end of the auction and the bid incremant is $2.50 in that range so the second highest bid was outbid using the eBay proxy bidding system by a single increment the highest bid may have been much higher than that in practice, that is just how the eBay bidding system works, the highest bid placed before the auction ends always wins.

Sniping only protects you against other bidders reacting to your bid, if they have already entered a bid that is higher than yours then they will still win.

I'd suggest you have a quick read of the eBay explanation on proxy bidding available here:

http://pages.ebay.com/help/buy/bid-increments.html
abcd1234
PostPosted: Wed Jan 14, 2009 11:15 pm    Post subject: outbid by the least amount - how could this happen?

Twice this week, I was outbid by the least amount in the last minute. How could this happen?

Bidder Bid Amount Bid Time
n***j US $133.50 Jan-14-09 14:49:39 PST
e***n US $131.00 Jan-14-09 15:12:10 PST
n***j US $130.00 Jan-08-09 12:12:56 PST
e***n US $125.00 Jan-14-09 15:11:46 PST

Thanks,
abcd

Powered by phpBB © 2001, 2005 phpBB Group