Riven drop rate is NOT 25%

[LordSajet]

That. Is. A. Lie.

After 4 ayatans, 1 reactor, 1x6k kuva, and 2x4000 endo i think its safe to say that riven drop rate is not 25%. Im not playing sorties anymore.

I want to keep playing this game, I really do. But between peanut vending sorties and bounties I just don't have the heart anymore.

 

Edited October 20, 2017 by LordSajet

[Spartan336]

RNG does not like you.

Just because you don't get it doesn't mean it's not 25%. You're just always getting the 75%. That's how the BS that is RNG works. 

[LordSajet]

Just now, Spartan336 said:

RNG does not like you.

Just because you don't get it doesn't mean it's not 25%. You're just always getting the 75%. That's how the BS that is RNG works. 

If im ALWAYS getting the 75%, doesnt that make it 100% ?

[NeithanDiniem]

So after 8 times you give up? Missing a 1 in 4 8 times is not unheard of you know. You are going to hate Warframe in general then

Edited October 20, 2017 by NeithanDiniem

[Spartan336]

Just now, LordSajet said:

If im ALWAYS getting the 75%, doesnt that make it 100% ?

Nope. That would mean you couldn't get Rivens. It's 25%. BS is preventing you from getting it. 

[NeithanDiniem]

Just now, LordSajet said:

If im ALWAYS getting the 75%, doesnt that make it 100% ?

No, it doesn't. It means you have not tried barely enough to make a real measurement.

[Xenotater]

Just now, LordSajet said:

If im ALWAYS getting the 75%, doesnt that make it 100% ?

No, you can get the 75% dozens of times in a row and it won't be 100%, that's just bad luck.

[puppycorpse]

Honestle it's all rng. Everytime I do it I just get pistol riven and I'm the opposite.  Idc for rivens so Im at a loss so I gave up on sorties.  That's how rng works though. 

[LordSajet]

1 minute ago, NeithanDiniem said:

No, it doesn't. It means you have not tried barely enough to make a real measurement.

Lol what does that even mean? How would I make a real measurement then?

[Spartan336]

Just now, LordSajet said:

Lol what does that even mean? How would I make a real measurement then?

Not just 7 times, that's how.

Warframe is a grind. RNG is bs, and the games not for everyone. You wont get anywhere unless you're willing to run them at least 100 times. Then I'd say you could make an accurate measurement. 

 

[NeithanDiniem]

5 minutes ago, LordSajet said:

Lol what does that even mean? How would I make a real measurement then?

Actually do it more than 8 times, for starters. You are dealing with RNG. You typically don't make real measurements of a percentage based draw with any less than 100 tries. Seeing as you have only gone 8 times it means you don't have nearly enough data to claim it isn't 25%.

Edited October 20, 2017 by NeithanDiniem

[Tain_OSkoom]

8 minutes ago, LordSajet said:

Lol what does that even mean? How would I make a real measurement then?

https://en.wikipedia.org/wiki/Sample_size_determination

[Nazrethim]

13 minutes ago, NeithanDiniem said:

So after 8 times you give up? Missing a 1 in 4 8 times is not unheard of you know. You are going to hate Warframe in general then

Before they buffed Rivens from whatever it was to 25% I achieved the dubious achievement of having 30 straight days of Anasa/Endo. Since then I haven't seen a Riven (granted, I do like 4 sorties per week, but still).

The rarity color indication is a lie.

[Gremlin]

I agree with the title. It feels a lot higher for me. Maybe 33%. 

 

Rng man, rng.

[Buff00n]

With a 25% drop rate you have about a 10% chance to go 0 for 8.  Hitting a 1 in 10 chance isn't even that rare.

With a playerbase in the millions, many of them running sorties every day, you will need a lot more runs in order to "prove" beyond statistical chance that the drop chance is not 25%.  To prove beyond a one in a million chance you would need to go 0 for 49.

With enough runs your results should even out.  I've run 92 sorties since U21 dropped and gotten 33 Rivens.  That's actually a bit more than 25%, but still within a 1 in 75 chance to get that many or higher.

[(XBOX)YoungGunn82]

It is what it is OP. Now If you did them everyday for 6 months and didn't get 1 riven, then you would have a leg to stand on. But only 8 times?....lol

[Ferah_Frithu]

It's because you seemingly don't understand the percentage mechanics behind such RNG-based sytems.

It's 25% per instance, and not cumulative. That means that it doesn't matter how often you try, because every single instance of the system choosing your reward has its own 25% chance.

Edited October 20, 2017 by Ferah_Frithu
Fixed typos

[(PSN)Oreic-Reynier]

That's not how odds work. 25% =/= 1 out of 4 guaruntee. 

[Patzer]

 

7 minutes ago, Buff00n said:

With a 25% drop rate you have about a 10% chance to go 0 for 8.  Hitting a 1 in 10 chance isn't even that rare.

With a playerbase in the millions, many of them running sorties every day, you will need a lot more runs in order to "prove" beyond statistical chance that the drop chance is not 25%.  To prove beyond a one in a million chance you would need to go 0 for 49.

With enough runs your results should even out.  I've run 92 sorties since U21 dropped and gotten 33 Rivens.  That's actually a bit more than 25%, but still within a 1 in 75 chance to get that many or higher.

Yep. Breaking this down, change of not getting riven in 8 rolls is 1-0,75^8 which is 10%~ (10,0112915....%)

If out of 121000 all time peak Warframe players, 80% are running sorties, it means there is 121000*0,8*0,1 = 9860~ players that are as unlucky as you OP.

[-AoN-CanoLathra-]

The OP is correct, but not for the reason he gives.

The actual drop rates for rivens are per riven type, all 4 of which add up to 25%.

The problem here is that percentages do not add that way.

The correct way to 'add' probabilities is to multiply their failure chances together, which then gives the total failure chance, which you can derive the success chance from.

So, doing this yields the following equation:

(1-0.0761)*(1-0.0136)*(1-0.0814)*(1-0.02)*(1-0.0679)

Which equals

0.7647034604

Which rounds to

0.7647

Then, to find the chance of success, we subtract from 1

1-0.7647

Which equals

24.53% chance to receive a Riven from sorties.

Which is not the 25% chance that DE loves to claim.

Q.E.D.

Edited October 20, 2017 by -AoN-CanoLathra-
Missed one value in the rather unorganized drop tables

[phoenix1992]

When did they say it is 25% to begin with?

[(XBOX)Tucker D Dawg]

4 minutes ago, phoenix1992 said:

When did they say it is 25% to begin with?

Xbox One Chains of Harrow: Update 21.0.5 (+Hotfixes) for Xbox One at any rate.  since xb is just a cut and paste of pc (less some usual performance tweaks) I'm sure a similar release for PC.

Quote

Melee Riven Mods are here!

Your Arsenal of Melee weapons has awaited the Riven treatment and the time has come! Rivens overall now have a 25% chance to be earned from Sorties.

 

[Buff00n]

41 minutes ago, -AoN-CanoLathra- said:

The OP is correct, but not for the reason he gives.

The actual drop rates for rivens are per riven type, all 4 of which add up to 25%.

...

Q.E.D.

In this case you actually can add percentages.  Each of the four possible Riven rewards is mutually exclusive; you can only get one from a single Sortie.  Mutually exclusive probabilities can be added.  In fact, all possible mutually exclusive probabilities for a particular event *must* add to 100%, which is true if you look at the complete Sortie drop table.

This is not to be confused with Void Relic percentages.  With relics, you run four at the same time and getting a rare from one does not exclude getting a second rare from another one.  In that case, where the outcomes are not mutually exclusive, you cannot just add the probabilities.  You have to basically multiply the inverse probabilities like you described.

If you want more detail then I wrote a spiel on this a few months ago.

Edited October 20, 2017 by Buff00n
Made link less ugly

[-AoN-CanoLathra-]

46 minutes ago, Buff00n said:

In this case you actually can add percentages.  Each of the four possible Riven rewards is mutually exclusive; you can only get one from a single Sortie.  Mutually exclusive probabilities can be added.  In fact, all possible mutually exclusive probabilities for a particular event *must* add to 100%, which is true if you look at the complete Sortie drop table.

This is not to be confused with Void Relic percentages.  With relics, you run four at the same time and getting a rare from one does not exclude getting a second rare from another one.  In that case, where the outcomes are not mutually exclusive, you cannot just add the probabilities.  You have to basically multiply the inverse probabilities like you described.

If you want more detail then I wrote a spiel on this a few months ago.

If I solo 10 Radiant Void Relics, I have a (1-0.9^10)~65% chance of getting one rare, because I rolled it 10 times.

The problem here (as far as I can tell) is that Warframe does not roll loot the way a D&D dungeon master rolls loot, I.E. roll between 1-100, then check a table. Warframe seems to roll each portion of the drop table sequentially, I.E. Did we get a Legendary Core? No? Next! Did we get a Shotgun Riven? No? Next! Etc. Etc. Until we get to the end, and if we didn't get anything, we give them an Anasa Sculpture.

On a side note, why are there 2 types of melee rivens? One has a 8.14% chance, the other has a 2% chance. I find that a bit odd.

Drop info here, for those that don't know.

 

[Buff00n]

6 minutes ago, -AoN-CanoLathra- said:

If I solo 10 Radiant Void Relics, I have a (1-0.9^10)~65% chance of getting one rare, because I rolled it 10 times.

Right, because each of those relic drops is not mutually exclusive.  Getting a rare from one does not mean you don't get a rare from the other 9.  Like I said, we already know you can't add those particular 10%s together.  

The Sortie drop table is different, because it's a single drop with only one outcome.

 

7 minutes ago, -AoN-CanoLathra- said:

The problem here (as far as I can tell) is that Warframe does not roll loot the way a D&D dungeon master rolls loot, I.E. roll between 1-100, then check a table. Warframe seems to roll each portion of the drop table sequentially, I.E. Did we get a Legendary Core? No? Next! Did we get a Shotgun Riven? No? Next! Etc. Etc. Until we get to the end, and if we didn't get anything, we give them an Anasa Sculpture.

Do you have evidence for this?  I'm pretty sure a single drop, such as a Sortie reward, does it fact operate from a single roll.

If they were doing the crazy thing you describe, and my math is correct, then the effective drop rate for Anasa would be somewhere around 50%, rather than the advertised 28%.  I know it seems like it drops a lot, but it does not drop that much.  

Since Sorties were reworked in U19 almost a year ago I have run 307 Sorties, and gotten 2K Endo/Anasa 112 times = 33%.  Since U21 it's 27 out of 92 = 29%.  I'm past the 1 in a million chance of that being a fluke and the actual drop rate being 50%.

 

8 minutes ago, -AoN-CanoLathra- said:

On a side note, why are there 2 types of melee rivens? One has a 8.14% chance, the other has a 2% chance. I find that a bit odd.

My guess is that the 2% is for Zaw Rivens, but that is purely a guess.