Profitable Prospectin’
Edit: The math wasn’t really wrong after all; just poorly laid out.
I wanted to take a look and see at what price levels prospecting might be profitable. For simplicity’s sake, and also from what I’ve heard in the Jewelcrafting circles, let’s keep this analysis exclusive to the big one, Adamantite Ore. From Wowhead’s data, it looks like each prospect has a 22% chance to drop a blue gem and an 80% chance for 1.37 green gems (either 1 or 2 green gems will drop).
Anyways, here’s what to do:
- Find out the average selling price of a blue gem on your realm (add up average prices of Talasite, Noble Topaz, Living Ruby, Nightseye, Dawnstone and Star of Elune and divide by 6). Let’s call this x.
- Find out the average selling price of a stack of Adamantite Powder (20). In my experience, this doesn’t sell too well, so you might want to vendor instead. Let’s call this z.
- Find out the lowest price you can get a stack of Adamantite Ore for (20=1 stack). Let’s call this y.
- 22% chance for a blue gem from 5 ore.
- 80% chance of 1.37 green gems every 5 ores= 4.38 gems per stack. 18 green gems=1 blue gem (Brilliant Glass). That means every 4.11 stacks, or 82 ores, you have a guaranteed blue gem. [1/(82/5)]=0.06.
0.22x + 0.06x + 0.05z= expected gold from one prospect (5 ores).
0.28x + 0.05z (simplified)
y= price of 20 ores (see above).
If [(0.28x + 0.05z)*0.95]>y/4, then prospect. Simplified: 1.064x + 0.19z>y.
If you’re vendoring the powder, use 1.064x + 0.9>y, then prospect.
NOTE: This is assuming the gems prospected sell on their first listing.
NOTE2: This will only work over a large amount of prospects. The main reason for this is so that the sample size is large enough to justify the equation but also that you get the necessary green gems for Brilliant Glass and so that you get enough variation in your blue gems.
I’d like to note a couple more things regarding patch 2.4.2. First of all, Brilliant Glass is now set to be on a 20 hour cooldown, which is a slight improvement, but which still may be a roadblock for getting rid of those green gems. An alternative would be using them to transmute Skyfire Diamond or Earthstorm Diamonds. Or, you could straight up sell them in the AH although this may be slightly riskier due to the huge supply. Secondly, I’d like to note that, according to the patch notes, there is now a slight chance for Brilliant Glass to yield an epic gem, which means that this may be even more profitable than it appears. However, I do emphasize the small in “small chance” and this shouldn’t be something you rely on.
Risk’ometer: 2
May 2nd, 2008 at 12:49 am
Actually, with 20% chance per 5 ores, you only have a chance of 100%-(100%-20%)^4 = 60% for a blue gem in a stack. Similar for greens.
May 2nd, 2008 at 3:07 am
Don’t vendor the adamantite powder!
Depending on your realm’s prices, it should be profitable to buy Primal Earth, Eternium Ore, and craft some Braided Eternium Chain for disenchanting purposes… I mean LOADS OF LARGES.
May 2nd, 2008 at 5:33 am
“20% chance for a blue gem from 5 ore= 80% chance per stack.”
That statement is false.
80% not getting a blue gem from 5 ore
40,96% = 80% ^ 4 = Chance of not getting a blue gem from a stack (20 ore. 4 attempts)
The chance per stack is 59,04%, not 80%.
The formula will have to be redone.
May 2nd, 2008 at 6:22 am
“20% chance for a blue gem from 5 ore= 80% chance per stack.”
*grins* Your last post contradicts that.
May 2nd, 2008 at 11:15 am
Love the site, but the math is wrong.
20% chance of a Blue per 5 ore does not mean 80% chance per stack. It’s 59%.
1 - .8^4 = ~59%
which should translate your final calculation to:
.789 + .9z > y
May 2nd, 2008 at 11:37 am
I’m somewhat surprised that after running the last article on drop rates, you would post something like:
20% chance for a blue gem from 5 ore= 80% chance per stack.
the math works out to about 60% chance, not 80%
(80% chance to NOT get a rare = 0.8. Using math from the previous post:
0.8^4 = 0.8*0.8*0.8*0.8 = 0.4096)
–
Gizmo
May 2nd, 2008 at 12:35 pm
You guys are raising it to the fourth, meaning you’re only calculating the chance of not getting a blue in four consecutive prospects. The math behind this post is based on averages and must be done on a large scale (hundreds of prospects) to yield accurate results.
May 2nd, 2008 at 2:46 pm
It doesn’t matter how many stacks you are prospecting, or if you are doing it consecutively or not. If the probability of prospecting 5 ore and getting at least 1 blue gem is 20%, then the probability of prospecting 20 ore and getting at least 1 blue gem is 1- (0.8^4) = 59.04%. The scale doesn’t change the odds because each prospecting is an independent event.
In other words, if you prospect X stacks of ore, the expected number of blue gems you will get is 0.5904 * X, not 0.8 * X.
The variancy of the number of blue gems you get is reduced if you do it hundreds of times, but the expectation remains the same.
May 2nd, 2008 at 6:48 pm
Paulo, the scale does change. Your 59.04% is the odds of getting ONE blue gem out of 20 ore. You aren’t taking into account that you could get more than one blue gem per stack.
I can’t easily give you a lesson in probability, but this magic 59.04% you guys are coming up with is irrelevant to our calculations. The last post was calculating the odds of getting (or not getting) ONE Badge of Justice in TEN Shattered Sun Supplies. We weren’t factoring the probability of getting two badges in ten supplies, or even three badges.
May 3rd, 2008 at 1:50 pm
I’ve made a spreadsheet to calculate the value of prospecting based on the exact numbers that Wowhead provides. I’ll get it uploaded in the next day or two so you guys can use it to calculate some accurate numbers.
May 4th, 2008 at 9:10 pm
The probabilities are as follows based on a 20% drop rate per prospect and with a total of four possible prospects the chance of a blue gem being yeilded are:
probability of 0 out of 4 = .4096 or 40.96%
probability of 1 out of 4 = .4096 or 40.96%
probability of 2 out of 4 = .1536 or 15.36%
probability of 3 out of 4 = .0256 or 2.56%
probability of 4 out of 4 = .0016 or .16%
If you are interested in the probabilities math is based on college level quantative business analysis 260 or equivalent, or poker hand chance probabilities.
(1/5)^0 x (4/5)^4 x 1 = .4096
(1/5)^1 x (4/5)^3 x 4 = .4096
(1/5)^2 x (4/5)^2 x 6 = .1536
(1/5)^3 x (4/5)^1 x 4 = .0256
(1/5)^4 x (4/5)^0 x 1 = .0016
the 1,4,6,4,1 based off of pascal triangle for possible combinations.
May 4th, 2008 at 9:15 pm
mind you i believe wowhead gives the original probabilities at 3% per gem for a total of 18%, not 20%, so the above calculations are not acurate based of wowhead data… however wowhead fails to give decimal places so they could be 3.33% each and total up to 20%.. This is of course theoretical. Without the deciaml places the total probability could be of by up to 3%.
May 5th, 2008 at 9:31 am
oh btw for a real good guide on JC and prospecting a guy in europe wrote up a 4 page post in the european forums. He simplefies the whole math issue on prospecting. However note that it doessn’t always apply to all servers, the prices he listed cost on avg 1.5x on my server making it more expenisve to level JC and the selling prices are not all that high either. too much competition and not enough people farming old world mats. his big seller the de into a large primatic shard on my server the mats go for more. sad but true.
http://forums.wow-europe.com/thread.html?topicId=2405312046&sid=1
oh also firgured out how to get a avatar! for anyone interested youll need to go to:
http://en.gravatar.com/
and register an account with your email, my understanding is that it goes acrooss all wordpress blogs.
May 5th, 2008 at 10:58 am
miyuji, your math scares me.
“probability of 0 out of 4 = .4096 or 40.96%”
“probability of 4 out of 4 = .0016 or .16%”
You are telling us that if you don’t prospect any ore you have more chances to get a gem than prospecting 4 times in a row?
May 5th, 2008 at 7:37 pm
Miyuji:
In the post you linked, Maxxer writes:
“You have 22% to get a blue gem from a prospect of 5 adamantite ore. “A” blue gem is worth 30.9, and 30.9 times 0.22 equals 6.8. So prospecting 5 ore is worth 6.8 gold in our example. That makes our average return on a stack of adamantite ore (20 ore) 6.8 * 4 = 27.2 gold. I wouldn’t buy ore if I had less than a 10% margin on just the blue gems, so I’d buy stacks of 24g or less in this example. However, see the ‘Demand and Supply’ part before you buy out 70 stacks of adamantite ore. For me prospecting accounts for approximately 35% of my JC profit. ”
He is also multiplying his result by 4 (to get expected value of prospecting 20 adamantite ore), so essentially, his math is the same as mine.
May 6th, 2008 at 1:41 am
To Tainha:
The probabilities are based off of exactly four prospects. Imagine a coin being flipped. 50% and 50% are our two probabilities, but if we flip it twice, we have three possible outcomes, HH = 25% HT or TH = 50% and TT = 25%. We treat the HT and TH as the same because for our purposes say we are looking for heads (aka blue gems) whether it comes on the first flip or the second it is still just 1 head (blue gem).
So when I say 0 out of 4 I mean that you have a 40.96% chance of getting no blue gems when prospecting four times. you must prospect four time to get this % of probability. Propecting once or twice or three time will all have different % probabilities for each potential outcome.
But let me make it SIMPLE.
All the proababilities above are based off of four propects, while fun to calculate for the layman IT DOES NOT MATTER! when wowhead says approx 22%, over the course of 100’s of prospects, YOU WILL PRODUCE A BLUE GEM 22% OF THE TIME.
The %’s or probabilities above are merely number expressing your odds when we go into multiple propects, similar to the coin toss. Over the course of dozens of stacks prospected, some producing 1, some 2, a couple stacks producing 3 blue gems and the rare stack producing 4 blue gems, when you take the number of gems add them up and divide by the number of propects it will equal 22%.
This whole conversation started with some people applying partial probabilites combination math and coming up with a number no one could understand. I had hoped to clear up the math and the odds on four prospects or a stack of ore, but i think i may have just confused some of you.
FOR THE PURPOSE OF DOING MATH TO FIGURE WHETHER A STACK OF ORE IS WORTH BUYING LOOK AT THE ABOVE COMMENT.
and yes Will, the math is the same as I use personally, which to be honest has nothing to do with probabilities math. Odds change the more times we flip a coin, however in the long run the averages will always be 50% and 50% for a single coin toss. The same applies for the a prospect, 22% each time.
May 13th, 2008 at 9:59 am
Taking this from one of the top Jewelcrafters on my server (I’ve got all the patterns except a few due to rep and I’ve made probably close to 20k on the profession), you really make more money from prospecting if you are in fact a jewelcrafter yourself, ideally an enchanter jewelcrafter. Enchanting comes into play if you actually use your dust to make Braided Eternium Chains and in turn disenchant them for shards.
Back on topic… For all gems including the dreaded talasite, there is a cut gem, if not 5 or 6 cuts, that are worth more than the material itself (which is a weird thing for professions). Taking it that a step further, if you’ve unlocked the alchemy lab with SSO, epic gems are also worth quite a bit more cut than uncut. I estimate there could be opportunities to make huge PROFIT margins (35G and up, possibly even 125G) per gem just from cutting the material.
May 20th, 2008 at 10:54 am
Just for reference here guys, I have a GIANT database of prospecting because im weird and I like to make databases. I’ve prospected about 20,000 ore and have received a droprate of 89% rare gems per stack of ore.