Item Cross-Check

Randall

Diabloii.Net Member
Item Cross-Check

I am doing a item crosscheck for all those that are interested in this.

I mean check all my items with all of your Items with all of ... items for double fingerprints.

With Flavie this step is not that difficult anymore.

What I want:
* A Flavie generated text output file of all characters/stashes
* The full atma dumps of all characters/stashes (Only for those without Flavie) And please zip these files as they can be huge.

The advantage of the Flavie option is it is one file and it's a lot smaller for E-mailing. How to create this file:
* In the third tab there is a line which ask for "Itemlist name (txt)" right below "Report name (html)".
* If you fill in this each time you create a report, a filename with this name is created (next to the report file). It will be a relative short file with FP and the item name of each item.

Note: I only want the text files with fingerprints, I do NOT want the real stashes/characters.

You can send this to this email: [email protected]

EDITED:
For now I am not sure how to handle found duplicates. As I can only edit for one hour check following post for the result.

Randall
 

Nightfish

Diabloii.Net Member
Randall said:
Unless the mods request me to do otherwise, I'll forward any found dupes to them.
Dunno, does that really say what you want it to say? Maybe I'm interpreting this the wrong way but to me it seems something like this:

- I send you my dump
- You check it and find a dupe
- You send that info to the mods
- My ass gets banned, along with the rest of me
- End of story

I know this is probably isn't what you were trying to say but that's kinda what it sounds like to me... If this is indeed what you are trying to say then I probably don't want my items checked after all ;)
 

Sledge

Diabloii.Net Member
for traders its handy

can't always be sure of these items especially if they are traded 3-4 times
 

Randall

Diabloii.Net Member
Nightfish said:
I know this is probably isn't what you were trying to say but that's kinda what it sounds like to me... If this is indeed what you are trying to say then I probably don't want my items checked after all ;)
@nightfish:
I just did not want to post the results in here, as with dupes it could end up with a barbeque thread which is also not what I want.

What could I do instead ?

Randall
 

Randall

Diabloii.Net Member
Another point of noting, The persons with dupes (I might find here) are NOT per definition cheaters. They are more likely persons who have gotten a bad item with trading.

Randall
 

Nightfish

Diabloii.Net Member
Okay, let's for a moment assume I duped an item on purpose... Now, why in the world would I be dumb enough to send you my flavie dump? Exactly, I probably wouldn't. (if you said "because you're a moron, fishy" I now hate you, btw :p )

So, what is the most likely source of any dupes you'd find with this? The way I see it there's 2 possibilites:

- I accidentally duped an item
- I traded for a duped item unwittingly

I fail to see why either of those would need mods to get involved. It would be enough to get back to me and tell me which items were duped and then I could take it from there. Either by trying to track back where the item came from or just deleting it from my end if I can't do that. You could then of course include that item in the dupe database but I see no need for any officials to get involved.

Dunno, I think at the weapons for toys program they don't ask you were you got your gun from either or burn you at the stake if you give it to the cops, right...?
 

Serdash

Diabloii.Net Member
Fishy:
I think the thing is, there have been some cases when someone would trade something, then forget to delete the mule, or intentionally not delete the mule, then later on, claim to find another of said item, and trade it again.

If a dupe is found among forum members, it can most likely be tracked back to the source of where it came from. I don't think any duplicated items will instantly result in you getting banned or anything. If anything, it should be discussed with the person first. As Randall said, items actually found to be dupes or hacked are most likely result of a bad trade or confusion during a trade.

Basically what I'm saying is if you're confident that you don't have duped/hacked/downloaded/whatever items, why not send them in anyways?

(Then again we all know you're a leet haxor)







And I still have yet to send mine in. Gotta do that sometime in the next week. :\
 

Randall

Diabloii.Net Member
Thanks Serdash,

they arrived just fine.

As I started this last week on 'a other site' I allready have a checked items to compare with.

Total items nr with Fingerprint: 36383

0 new duplicates (total: 1 duplicate found)

Randall
 

Artagas

Diabloii.Net Member
I will send mine shortly. My suggestion is that if you find duplicates, you just email the players involved, before doing anything else. (or do you even want the dumps from people who don't trade/participate in giveaways?)

Btw, what is the chanche of two items of the same type actually dropping with the same fingerprints? If the letters/numbers in the fingerprint were all generated independantly of the item in quesion, it would be easy to do the math, but i suspect it is not the case.
 

Nightfish

Diabloii.Net Member
Yeah, I wanna see the odds of 2 items having the same fingerprint vs the odds of a tyrael's might or a zod rune dropping. :)
 

Artagas

Diabloii.Net Member
well, if all the 8 characters (letter/number) were generated independantly, than the chanche would be (very) roughly 17 times smaller than Baal dropping 2 Tyrael's Might in 2 runs on player1 with 0 mf. in other words, if 1000 of us were playing and saving 10 items every hour, we would need an average game time of 32,000 years/head to have 2 items with the same fingerprint in our stashes.
so pretty small:)

but is that the case?
 

maxgerin

Diabloii.Net Member
Text files sent! :)

Thanks for doing this, Randall! :thumbsup:

EDIT: I know this is not the place for this, but don't want to post again in the right thread... :teeth:
Question on Flavie...
Why is it that it doesn't seem to recognize Antidote? I'm sure I had one in one of my stashes when I encountered this problem, but the report shows none...

--maxgerin
 

Randall

Diabloii.Net Member
Don't ask me though, I've don't know how a fingerprint is created for an item.

From the Flavie I've learned that fingerprints can be equal on different items. At least nobody could (or has tried to) prove the opposite.

For all items I tested upto now I've seen 1 item with the same fingerprint. (the magical item in case were identical as well). No 2 different items with the same fingerprint is found yet.

Randall
 

Randall

Diabloii.Net Member
@maxgerin:
I guess nobody ever looked at the amount of antidote bottles, I am one of them. I might check to see why though.

Total items nr with Fingerprint listed: 44029

0 new duplicates (total: 1 duplicate found)

Randall
 

Randall

Diabloii.Net Member
@Artagas:

Is that the chance a Fingerprint could be double or is that the time where if you give each item a new Fingerprint all possible Fingerpints are used.

EDIT:
It looks like it is a hexidecimal code with a maximum size of 8 characters.
EDIT2:
8 hex = 4.294.967.295 possible numbers in the decimal value
8hex = 64 bits for setting information

Or a combination of this offcourse.

Randall
 

Nightfish

Diabloii.Net Member
Randall said:
Don't ask me though, I've don't know how a fingerprint is created for an item.
No no, we're not asking you. It's kinda like fishing: You put your bait in the lake and wait until the appropriate fish comes along to devour it. In this case the lake is just a random thread on the forum, the bait is a technical question and the appropriate fish is RTB, Thrugg or Shade. Sooner or later they always sniff out these questions we hide in random threads. :teeth:
 

Shakes

Diabloii.Net Member
Artagas said:
well, if all the 8 characters (letter/number) were generated independantly, than the chanche would be (very) roughly 17 times smaller than Baal dropping 2 Tyrael's Might in 2 runs on player1 with 0 mf. in other words, if 1000 of us were playing and saving 10 items every hour, we would need an average game time of 32,000 years/head to have 2 items with the same fingerprint in our stashes.
so pretty small:)

but is that the case?
Actually, we're talking an 8 digit hex number here, in other words 2^32 combinations.

A side question for you: If 19 people where in a room, what's the odds of one of them sharing the same birthday? Most people would think pretty low, but actually it's about 50/50. When looking for a duplicate in a set, the probably reaches 50% at the square root of the set size.

This applies to item fingerprints, so 2^16 or 65536 items for a 50% chance of one of them matching coincidentally. Assuming their perfectly random, which they probably aren't due to the imperfections of a pseudo-random number generator, which may skew things to make it slightly more likely.

Since (according to ATMA) Tyrael's is a 1 in 409739 drop, if people did 100000 baal runs and picked up the best drop from baal each time, you'd be far more likely to find a duplicate fingerprint (although not necessarily on the same item) than you'd find a Tyrael's.

Of course items would need to have exactly the same stats to be falsely detected as a dupe, so the chances are low. But for items that many people have but the item hase few (or no) variable properties, the chance is certainly non-negligable that a dupe will be detected even though no duplication has taken place.

The moral of the story? Fingerprints are helpful but not foolproof. Human judgement is still required before you can draw any conclusions.
 

Artagas

Diabloii.Net Member
well, sorry if i mislead anyone. i did not realize it was a hex thing to begin with, and what i posted was the chanche of matching a certain fingerprint.

either way...if you have 'k' items in your stash, and there is 'n' possible fingerprints total (according to Shakes, 2^32) than the chanche of two or more being the same is: (supposing k<n)
1-(chanche of all of them being different) =
1 - (n/n)*((n-1)/n)*((n-2)/n)...((n-k+1)/n) = 1 - n!/((n-k)!*n^k)
now my guess is that claiming that the above equals approx. 0.5 if k = n^0.5 is a pretty bad approximation.
It'd be rather hard to use the above formulae if n is large enough, so you probably want to approximate anyhow...using Stirling's formulae or something similar. If you want further details, i will give you some, but since this is not a math forum i tought it'd be best avoided.

edit: for your birthday example n = 365 and k = 19, and the above would be 1-0,62 = 0.38, so not quite 50%, but still more than what people intuitively think.
 

Randall

Diabloii.Net Member
Following the next calculations

n = 2^32 (possible fingerprint numbers)
k = 44000 (number of checked items)

gives me a 20% chance of a double between 2 random items.

For 65.000 items the chance is around 40%
For 100.000 items the cance is around 69%
For 200.000 items the chance is around 99%

That is only the chance if it's a random number.

It could be done different, just an example:

Out of 64 bits I could create a date/time part with 44 bits (day, month, year, hour, minutes, seconds) and a random number of 20 bits: That means there are around 1.000.000 possible random numbers for each second.

1000 items created in the same second gives 0.38% chance of same fingerprint.

EDIT: Calculation error corrected

Randall
 
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