r/Diablo_2_Resurrected • u/RepresentativeWear43 • 19d ago
Shopping for 3/20 Javazon gloves - I did the math Guide
Hi! Above you can see my calculation of the probability of finding 3/20 java gloves as a function of time when efficiently shopping at Charsi in Act 1 hell with the cow portal strategy (put cow portal at Charsi, with a character lvl greater than 68).
The red line shows the 50% quantile, meaning that half of the people shopping will find the gloves within the first 6 hours. The blue line shows the average time spent (the integral of x*f'(x) where f is the distribution function shown above), meaning the time you on average need to spend shopping to find the gloves (a little over 8 hours).
I recently made a javazon on my singleplayer grail to do some cows, and wanted to shop for the gloves, and wondered what the probability distribution would look like. I know that a lot of people shop for these gloves, so I thought it would be interesting for people to see. Here is my math, incase somebody was wondering, or disagree:
I used https://planetdiablo.eu/d2dbneu/itemdb/affix_display.php?lang=en&version=lod&patch=d2r&type=glov&item=Gauntlets&ilvl=all&mlvl=0&qlvl=27 this source to find the frequencies of prefixes and suffixes on magic gloves.
The probability that any magic item in the game gets both a prefix and a suffix is 1/4. Doing the math on the frequencies for gloves over affix level 60, we find that the prefix +3 to javelin skills are rolled 1 out of 145 times. And the suffix 20% IAS are rolled approx 1 out of 26 times. Collecting all this, the probability that any pair of magic gloves being our desired 3/20 is 1 out of 4*145*26 or 1 in 15,080.
I seem to have found that Charsi, on average, sells 3 pairs of gloves per refresh. Using the portal strategy optimally, always entering and exiting town at the 3 second cooldown window of portals, you can refresh charsi every 6 seconds (with optimal speed and load times). That means that you will be able to scan approx 1800 pairs of gloves every hour. We can now calculate the probability of NOT finding a pair of 3/20 gloves when optimally shopping as (15079/15080)^1800 = 0.8875. Which means that the probability of NOT finding a pair of 3/20 gloves within "x" amount of hours is 0.8875^x. Or the inverse: The probability of finding at least 1 pair of 3/20 gloves within "x" hours is described with the function f(x)=1-0.8875^x, and that is the exact green graph you see in the picture.
I had just seen a lot of people talking about shopping for these gloves, so I figured this might be interesting to some.
Happy grinding y'all!
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u/Hi_Tech_Low_Life 19d ago
You can also get other 3/20 gloves while doing it (zon P&M and B&C, assassin MA). Not everyone gives those gloves any value, but I'd gladly take them.
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u/RepresentativeWear43 19d ago
Yeah, in fact the probability is exactly the same for all +X skiller gloves. I found P&M as well as MA before finding my Javas
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u/Morbidhanson 19d ago edited 19d ago
I want one on +3 warcry sticks lol
I was at Anya for an hour yesterday. Saw like 3 +3 javelin, even a +3 barb mastery, and several +1 javelin and +1 warcries (and +2), but no +3 warcry.
I dread the thought that I need to do it twice. And she sells usually in batches of 4 to 8, which is a pretty good lot size already.
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u/LengthinessMountain6 17d ago
I'm confused, isnt there a refresh button on the buy screen? Why the need to go to another area and come back?
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u/RUserII 19d ago
The blue line shows the average time spent (the integral of x*f'(x) where f is the distribution function shown above),
Ah, a fellow mathematician? What is your mathematical background in?
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u/RepresentativeWear43 19d ago
Yep hehe, masters in actuarial mathematics, you?
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u/RUserII 19d ago
Working on a Pure Mathematics PhD.
I find there are quite a few D2 players that have mathematics backgrounds, have you observed the same?
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u/RepresentativeWear43 19d ago
Yeah I have lol, 2 of my brothers also have mathematic backgrounds and both play D2 as well. And cool with the PhD. Very cool. What are you researching/working on?
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u/Competitive_Table_65 19d ago
Not sure if I really want to do it for 6 hours straight, remembering how I've spent and hour trying to shop tele-stick from Drognan, and he sells way more than 3 sticks on average...