i just splashed out on buying 5 packs of 1st edition Japanese expedition sealed packs. upon arrival i soon realised that none contained a single holo!!! considering how many holos this series has i find it hard to believe that these where not weighed.
what is the likely hood of getting 5 non-holo packs in a row?
12.5% chance or 1 out of every 8 times you buy exactly 5 random packs online for this set.
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I noticed most packs sold on ebay are weighed. I am not sure what the holo ratio is for japanese booster packs, but out of 5 packs I believe you should have gotten at the very least 1 holo!
That sucks, yangumbreon. So many weighed packs out there on eBay. 
Which seller did you buy it from?
Try finding a better and honest one.
dont buy sealed single boosters online unless you are 100% sure they are reputable…even then its always dodgey to buy and open…if you buy to grade/keep sealed sure go for it.However dont be surprised when you get jipped if you open 
sorry dude…just be very wary in future
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That’s exactly why I never bought loose packs on ebay. If you get bad pulls, you can never tell if the seller conned you or you were just unlucky. Recently I opened 6 booster packs in a row of guardians rising, 0 holos. I then thought how if I bought it loose I would have thought I was scammed. Fortunately for me, it was just my terrible bad luck
Rule number one: Always assume every loose pack on eBay is weighted.
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I believe it’s closer to 13.2% -
P(noholo & noholo & noholo & noholo & noholo) = P(noholo) * P(noholo) * P(noholo) * P(noholo) * P(noholo) = (2/3)^5 ≈ 13.2% chance that you get no holos after opening a set of 5 packs, where the P(noholo) = 2/3 [2 out of every 3 packs contains no holo]
since opening a pack has no effect on the probability on getting a holo in the next pack (i.e., the events are independent), we can just multiply the 2/3 probability by itself for the # of pack openings
Now, with the given information that the packs were bought off ebay, P(noholo) is likely to be much higher 
For example, if we assume that P(noholo) is closer to 95% [i.e., a large majority of the single packs have been weighed, so on average 95% packs being sold on ebay do not contain holos], then the probability that you buy 5 packs and don’t get a holo jumps up to (0.95)^5 ≈ 77%. As others have said, the best thing you can do is not buy single packs off ebay, unless you can glean from the seller’s sales history that they are unlikely to have weighed the packs.
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I did .66^5 and 12.5% is close to 1/8 which is easier to relate to.
Just have gemmintpokemon buy them for you next time, you’ll get 5 holos.
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I opened more from different sellers with no holos 
If we’re going to be nitpicky about statistics… (lol)
You have provided P(5 nonholos | ebay purchases) = 77%. Really though, OP is more concerned with P(weighed | 5 nonholos) (i.e. was this a con job???)
For the sake of this post, I will assume the following. Feel free to change any of these numbers if you feel they are inaccurate (I’m just making them up):
- probability of buying a weighed pack on ebay from unknown seller = 0.60
- probability of getting a nonholo from a weighed pack = 0.98
- I will also assume the seller will either sell 5 weighed packs or 5 unweighed packs, for the sake of simplicity (also a pretty reasonable assumption)
Let’s bust out some Bayesian statistics:
**P(weighed | 5 nonholos) = P(5 nonholos | weighed) * P(weighed) / P(5 nonholos)
P(5 nonholos | weighed) * P(weighed) = 0.98^5 * 0.6 = 0.542
P(5 nonholos) = P(5 nonholos | weighed) * P(weighed) + P(5 nonholos | unweighed) * P(unweighed)
P(5 nonholos) = 0.98^5 * 0.6 + (2/3)^5 * 0.4
P(5 nonholos) = 0.595
0.542 / 0.595 = 0.91**Therefore there is a 91% probability the packs were weighed (GIVEN THE ABOVE ASSUMPTIONS!!!)
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I was bidding on a few packs of Japanese 1st ED Expedition over the last week too, must’ve been from the same guy. Good to know and am glad I didn’t bother to bid any higher.
I could be wrong, but I thought the Japanese packs had 50% holo chance
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Pull rate seemed to be 1 in 2 packs from the box I opened up.
All this calculation, guessing and personal experiences… yes pull rates can be calculated but only from a sealed box. Guessing is the same thing. Personal experiences can vary depending on how many times packs has passed from seller to seller and how honest the seller is.
I stick with my earlier statement: ALWAYS assume packs to be weighted.
Yeah unfortunately most loose packs are weighed.
What do the eBay sellers here think about leaving reviews stating that you suspect they’re weighed?
Considering there’s a chance that you would be leaving a legitimate seller damaging feedback, I’d say you shouldn’t
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That’s what I was thinking. I’ve never done it before. But then again I’ve never expected to pull a holo (happened once or twice which was a nice surprise). I’ve left feedback stating I did pull a holo for those sellers.
I guess if you were to buy a number of packs far in excess of the above calculations with no holo pulled and no notice of weighed status then it may be a different story?
Yes, 100% of all packs are weighed so please don’t complain when no holos appear. If a holo does appear, it’s an oversight by the seller.
Buy boxes to be sure.
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