Actually, everyone should read up on cumulative probability - a lot of bad math in here.

 

Cerion has the math right.

 

Odds are multiplicative when calculating multiple events. This is the general formula for independent events:

Chance to get schematic = 1-((1-p)^n)

p = RE rate

n = number of items RE'd

When working with the formula, remember that the numbers are not % numbers. So 20% RE rate is 0.2, and a final probability of .64 is 64%

 

So if you have a 20% success rate, the probability getting a schematic by RE one item is 20%

Probability of getting one by RE 2 items is 36% (NOT 40%)

3 item is 48.8%

4 item is 59.04%

....

20 item is 98.85% chance

Please understand that. Out of ALL crafters that RE 20 items of a 20% item, 1.15% of them will NOT get a successful recipe.

 

So yes, you are very unlucky if you are RE 20+ items and not grabbing a recipe, but you are in the realm of possibility.

 

Let's put this another way.

If you want a 99.95% chance to RE a recipe, you need to RE:

34 items of a 20% chance

74 items of a 10% chance

150 items of a 5% chance

 

Even at 99.95%, 1 in every 2000 people will still not have a recipe.

Could not have said it better myself!

I say those are the wrong parameters (and you apparently agree with me in your last paragraph) because they were the wrong parameters for the question asked. For 0 schematics after 25 attemps, a = 0, and b = 0. So are you just trying to stir up trouble or what? I mean, you say you don't understand and then you say you agree with me??

I didn't say I agree or disagree with you, nor I'm trying to stir up trouble.

[...]

 

Probability of Success: 0.9999999998285%

So after 25 attempts we have a near 100% Probability for a schematic. [...]

 

In Ironcleaver's post is not explicity stated what's the "question" (at least not to me), but the wording in that bit makes me think in something like "at least 1". Definetely doesn't look like the question is "chances of getting 0 schematics"

And then, your first response to Ironcleaver's post

I don't believe you're using that linked calculator correctly. You're trying to discover the probability of zero successes. You need to enter zeros in both fields. At least 0 successes, and at MOST zero successes after 25 trials.

[...]

You are asking a specific question that is different from the one Ironcleaver was asking. "At least 1" is different from "exactly 0". You change the question, then the parameters change. Doesn't mean the others were wrong.

That's why I said I don't understand why you say Ironcleaver's parameters were wrong.

To the OP:

 

Your basic assumption is that the code is all working as intended and that people are just totally deluded (or are just lying).

 

That is not math. That is not rationality -- it is blind faith that everything within the game works as it's intended.

 

Your post tells us more about yourself than about anything else.

/salute

The thing is at lower levels you can easily, very easily get better schematics on any crafting profession. But at level 50, you basically get squat!

So what's the difference? It gets tougher as you go up? There's no indication from BioWare that this is the case. Regardless, of the math and of the percentage, it's unbalanced the way it currently is.

Oh...I forgot...."It's working as intended." BioWare's favorite line.

In Ironcleaver's post is not explicity stated what's the "question" (at least not to me), but the wording in that bit makes me think in something like "at least 1". Definetely doesn't look like the question is "chances of getting 0 schematics"

No. There is no explicit question, but it is implied with his statement:

The Probability of REing even 100 items at 20% chance of success, chance of failure so insanly small it's infinitesimal

So I looked at his result and I knew intuitively that he'd entered something wrong. This statement implies he wants to know the chance of utter failure after x number of tries. That requires a=0;b=0. In a subsequent post, he even clarifies that he wanted to enter a=0;b=25, because his link stored his previous settings of a=1;b=25.

You are asking a specific question that is different from the one Ironcleaver was asking. "At least 1" is different from "exactly 0". You change the question, then the parameters change. Doesn't mean the others were wrong.

No. No, I'm not. He never asked that question. Nor did his entered parameters reflect that question.

That's why I said I don't understand why you say Ironcleaver's parameters were wrong.

His parameters are wrong because he entered a = 0 and b = 25. Those parameters aren't the same parameters you're talking about a = 1; b = 25. His parameters essentially ask the question: "What is the probability of all events after 25 attempts" All events include 0 success, 1 success, 2 successes...etc. Of course the solution to THAT question approaches 100% because, uhmm, it includes all POSSIBLE events. It's like asking, what's the probability of a coin turning up heads OR tails when flipped. That probability is nearly 100%, ignoring black swan events.

His parameters are wrong because he entered a = 0 and b = 25. Those parameters aren't the same parameters you're talking about a = 1; b = 25. His parameters essentially ask the question: "What is the probability of all events after 25 attempts" All events include 0 success, 1 success, 2 successes...etc. Of course the solution to THAT question approaches 100% because, uhmm, it includes all POSSIBLE events. It's like asking, what's the probability of a coin turning up heads OR tails when flipped. That probability is nearly 100%, ignoring black swan events.

It does not just approach 100%, it is 100%. What you're looking at in the calculator is a rounding error since it's calculating numerically, and quite obviously printing at higher precision than it can really calculate at. I suspect the author doesn't really know how floating-point math in computers works.

In the real world the coin can land on its side, but when dealing with probability math, it's usually better to assume an idealized coin which has exactly 50% chance of both heads or tails, and thus an exactly 100% chance of turning up one way or the other when flipped.

Applied SWTOR Mathematics

I don't subscribe to the law of averages when the processes are truly independant, so it's entirely realistic that someone may take 30 attempts to RE at 20%.

However, as most people won't be running statistics on their attempts vs successes, we do have to rely on perception of the userbase to identify a bug in RE if they occur, so we'll have 100% probability that 'RE is broken?' threads will continue to appear.

It does not just approach 100%, it is 100%. What you're looking at in the calculator is a rounding error since it's calculating numerically, and quite obviously printing at higher precision than it can really calculate at. I suspect the author doesn't really know how floating-point math in computers works.

 

In the real world the coin can land on its side, but when dealing with probability math, it's usually better to assume an idealized coin which has exactly 50% chance of both heads or tails, and thus an exactly 100% chance of turning up one way or the other when flipped.

You are of course correct. I tend to hedge my words a little bit on forums like these because you always have the guy that says 'what about the chance that a bird flies by and snatches the coin in mid-air' or some such thing, and then uses this strawman to refute an entire argument. That's why I mentioned black swan events like a coin landing on its side as you pointed out.

Law of Large Numbers

Bernoulli Trial

Online Bernoulli Calculator

• 20% chance for schematic while REing (80% fail rate).
  
• 25 attempts (or rolls of the dice) - online calculator limit
  
• Can have Zero Successes
  
• All can be successes,

Formula:

P(A) = ∑bi=a(ts+i)(p)s+i(1−s)t−s−i = ∑25i=0(25i)(.2)i(0.8)(25−i) = (250)×(.2)0×(0.8)25+(251)×(.2)1×(0.8)24+(252)×(.2)2×(0.8)23+(253)×(.2)3×(0.8)22+(254)×(.2)4×(0.8)21+(255)×(.2)5×(0.8)20+(256)×(.2)6×(0.8)19+(257)×(.2)7×(0.8)18+(258)×(.2)8×(0.8)17+(259)×(.2)9×(0.8)16+(2510)×(.2)10×(0.8)15+(2511)×(.2)11×(0.8)14+(2512)×(.2)12×(0.8)13+(2513)×(.2)13×(0.8)12+(2514)×(.2)14×(0.8)11+(2515)×(.2)15×(0.8)10+(2516)×(.2)16×(0.8)9+(2517)×(.2)17×(0.8)8+(2518)×(.2)18×(0.8)7+(2519)×(.2)19×(0.8)6+(2520)×(.2)20×(0.8)5+(2521)×(.2)21×(0.8)4+(2522)×(.2)22×(0.8)3+(2523)×(.2)23×(0.8)2+(2524)×(.2)24×(0.8)1+(2525)×(.2)25×(0.8)0

Result:

0.00377789318629571+0.02361183241434800+0.07083549724304400+0.13576803638250100+0.18668105002584400+0.19601510252713620+0.16334591877172800+0.11084187345224400+0.06234855381688725+0.02944237262043000+0.01177694904817200+0.00401486897140800+0.00117100344999400+0.00029275083649700+0.00006273228867600+0.00001150090324680+0.00000179700081000+0.00000023783834250+0.00000002642407900+0.00000000243335400+0.00000000018223590+0.00000000001075250+0.00000000000046000+0.00000000000001500+0.00000000000000000+0.00000000000000000 = 0.9999999998285

Probability of Success: 0.9999999998285%

 

So after 25 attempts we have a near 100% Probability for a schematic. Issues is, a lot of people are REing a lot more then 25 items, some upwards of 200 items and still get nothing. The Probability of REing even 100 items at 20% chance of success, chance of failure so insanly small it's infinitesimal.

 

Sure Probability is Probability though....... :-/

 

It's 4am and Im bored. :-/

Good post, but that assumes the randomizer follows law of probability, but ultimately it's based on the algorithm they use and the clock on the server.

Good post, but that assumes the randomizer follows law of probability, but ultimately it's based on the algorithm they use and the clock on the server.

Aye thats the wrench in the gears at the moment and the 10 million taun-taun question; it could be the root of all the issues (or preceved issues). I hope they know better though, a random system based solely off a system clock (client or server) is a very bad idea. If other variables are also mixed in then the system becomes stronger and the more the better.

Based solely off a system clock can cause patterens in the randomness like those that play at a certin time of the day have a higher probablility of "succeeding" that those that play at different times. This is becasue there is only so much data a "seed" can pull from a clock and that clock repeats pretty often and has only limited numbers.

Example: If the clock says 12:00 for our seed, the "random number", lets say, returns a "4".... The issues is that this happens every time we "ping" the clock at 12:00. The numbers appear random becsaue the clock is in motion. Ping the system clock fast enough and you can get say a dozen "4's" becsaue the clock hasn't changed. So when asking for several random numbers add an artificial pause in ms giving the seed source enough time to change.

A good solution is to use the clock as a base source then add several other sources that can also change on their own and tie them all together as a source for a single seed.

long story short - Yeah.

I do have first apologies to everyone in this thread as I was traveling since I posted my comments and could not respond sooner to various future comments.

I wish folks would stop quoting Ironcleaver's formula. While the formula itself is accurate, he entered the wrong parameters for the formula. a and b should = 0, NOT b=25.

I have to agree with you on the 0 and 25 logic. As a Six Sigma Green Belt it was my personal intention to place a stake in the ground to hope that the Development community would find a moment to at least comment in this thread, but you know how they are.

The cumulative chance approach, while a decent simulation of learning from mistakes, seems to require a database addition for each person RE an item, and for each item. Not a quick undertaking for the devs. But I'm not a programmer, so I don't know.

Trust me on this we could be looking at one Developer spending months in what is commonly call FTE (Full Time Employment) on this one item.

Now on the other hand are we factoring as I implied life learning or as others comment probability tables? If we look at the comment below:

... we have a 1 in 5 chance of getting a "schematic or crit" in a single attempt - but us as players are stringing the events together so probability-chaining has to come into play.

I honest believe that this would require the additional mathematical formula and tables that I spoke of and again we see the loop back to the need for FTE development effort.

We know flipping a coin once is 50/50. Flipping the coin and asking for at least 1 in 25 flips be "heads" is another ballgame. Could you flip the coin 25 times and only ever get Tails, yes, but it is the odds are ungodly low of that happening. This is the issue people are having when they RE 40 items without hitting that 20% - it can happen but the probability is extremely low.

In the real world the coin can land on its side, but when dealing with probability math, it's usually better to assume an idealized coin which has exactly 50% chance of both heads or tails, and thus an exactly 100% chance of turning up one way or the other when flipped.

Exactly cause in reality I think you nailed the head here (no pun intended), but again it is a probability table and not a life learning and improvement table that is being applied. Cause it did not factor the third outcome just either Heads or Tails.

I think the simplest way would be the addition of "Crafting XP".. it would only add a single variable to the object and would have pretty low overhead in programming. Basically if you RE 15 of a single item you gained enough XP for that item to unlock the next stage. Since going from green to blue gives three different schematics and going from blue to purple gives 5 (just an example) - just let the player choose which they wish to unlock.

 

Remove the randomness altogether but still make people invest time, effort and resources.

 

Clean and simple and wouldn't add much overhead to the code of done correctly.

 

[edit: basically the crafting xp would be the representation of the "simulation of learning from mistakes"]

This solution while you imply simply and clean creates a few issues and problems. First it does create the ability to choose the path you desire much like the Advanced Class and other similar items within the game, but it also opens the door to other factors that MMO's face, so the challenge is removed. Additionally here you assume a flat formula to go level to level. I need "X" resources or "Y" type to get what I desire. I do not need to worry about variables of sufficient funding and hunting. Additionally based strictly on your comment, it is a flat formula thus 15 times at level 1, 15 at level 2 and no accounting for knowledge gained. This also does not help to provide another avenue of possibility the AUGMENT ability.

This should be a factor as well. I see on the GTN and the HTN all the time AUGMENT items more than I see none. So those have to be accounted for and factored as well.

But remember in the end even RSA had problems with their probability tables. So not everything works every time.