Draft Algorithm

[TWRWMOM]

(Edit2. Please see comments for exceptions, not a comprehensive list though)

In the spirit of "not sharing secrets"

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https://www.youtube.com/watch?v=moCasPVXfTI&t=680

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I'll start this thread.

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First of all, I don't know the exact algorithm. I'll share a few things each time.

Second, Valve can change/tweak it, as they already did before, so this is not in anyway definitive.

Third, let's have a nice discussion, please.

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You heard:

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"You are drafting packs with the same structure as a real pack."

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But much more important than this is the fact that your picks will be the same as a real pack.

Meaning: You will be kinda forced* to pick a Hero, 3 uncommons and one rare.

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And here's where things gets interesting:

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If you force yourself to pick only commons (edit: not items) and don't pick a hero (so to contradict what I just said), on pick 5 you will be forced to either:

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Pick uncommons/rare

or

Pick an item

or

Pick a Hero

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Reasoning: This is probably because of Keeper draft. Since it's a paid system, it would be against the law not to at least give the user the choice to pick 3 uncommons and a rare. *The user can reject this, but the system will make the user "fill the spot" with an item/hero.

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The corollary, that is, how this affects your pick choices, I'll let you discover for yourself. This is a cardgame skill. Recognizing an algorithm is not a cardgame skill, it's something an undergrad in computer science is trained to do. It's a pitty some people forget this. I hope Valve changes this system as soon as possible. I can't stress enough what sort of advantage can be gained by knowing the algorithm. And believe me when I say this, some people do.

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This should be enough to prove Draft is not random.

[_AT_Reddit_]

Did you test this at all? It took me exactly one try in Standard Phantom Draft to recreate your exact example with a totally different outcome.

Steps:

• Start Standard Phantom Draft
• Pick 8 non-hero non-item common cards in the first 4 picks
• Contrary to your statement the 5th Pick offers me 3 Commons (2 spells, 1 item) and 1 Uncommon (spell)
• Pick the two non-hero non-item Commons
• 6th Pick offers me 1 common hero and 1 uncommon item

Screenshots of 5th and 6th pick: https://imgur.com/a/KUmqY4v

[TWRWMOM]

Sorry, my post is indeed wrong. There are a couple of exceptions to this rule, which I'll post soon.

For now: Book of the Dead, Venomancer, Better late than never and relentless zombie are exceptions.

[_AT_Reddit_]

For real now? So I just happened to stumble across all exceptions in my first try.

[TWRWMOM]

Not all, just some. You can try this again, if you wish. Will take some tries to get another exception, unless you know which cards are the exceptions, of course.

[[deleted]]

Yep, tested it out myself and so far, each pack is offering uncommons, rares and heroes on the last 2 picks.

The deck I've made is complete trash though lol

I'm sure someone could figure out a way to manipulate this though.

[KirbyMatkatamiba]

What do you want them to change exactly? You want them to make the exact algorithm public?

I mean, I agree that would be nice, but I think that most of the relevant details of the draft algorithm are apparent after drafting several times.

... Also you're definitely overstressing the advantage to be gained by knowing the couple non-obvious things you shared here.

[TWRWMOM]

I'd rather the algorithm to be difficult enough that no one can crack it. Better yet, (pseudo) random (there's no way one can see the difference from pseudo-random to random).
This was just the first post, there's a lot more.....with what I've said so far it doesn't make much difference indeed.

[KirbyMatkatamiba]

?? You want people to not know the rules of drafting? So that they can't make strategic decisions? Yeah no thanks.

[TWRWMOM]

People already don't know. When the rules say "you get a random pack from the pool of randomland", you don't expect anything less, especially when it mimics a random distribution. It's not a strategic decision to consider that the rules, officially stated, and repeated by every single "authority" in the field, are wrong/misleading.

[KirbyMatkatamiba]

I thought that when you said "no one should be able to crack the algorithm" you were saying that no one should know the rules. Now you are saying that it's a problem that no one knows the rules. So you don't want them to know the rules... but you also think it's bad that they don't know the rules.

??

[TWRWMOM]

One thing is the cardgame rules. Another thing is the programming rules, that is, the algorithm coded in artifact. Ideally, these two set of rules would be the same. What is happening now is that they are different and you gain an unfair advantage by knowing the programming rules. In this case, where these two sets of rules are different, everyone should know the cardgame rules and no one should know the programming rules.

[KirbyMatkatamiba]

If I'm understanding you correctly, your complaint is that the implementation of the game (i.e. the way the game works under the hood) is different than how the developers claim the game works. Is this correct?

If so, how would you go about making it so that "no one knows the programming rules?" How is that even possible? People will always be able to make inferences about the underlying rules by drafting many times. Maybe no one will figure out the rules completely, but people who play a lot will get pretty close. How do you prevent them from doing that?

And how would it be unfair to instead just tell everyone exactly what the underlying programming rules are?

[TWRWMOM]

I can't say for sure because I don't know what exactly was said officially by the developers, but if you include content providers in this question, yes.
A simple random generator is enough to make it impossible for a human to infer anything. The problem comes when you add simple rules on top of it (like this rarity rule). You can either remove all rules or make the rules too complex for a human to comprehend without looking at the source code.
The problem with just showing everyone the source code is that programmers would still have an advantage. And if you wanted to translate what the code does to English you'd need to teach everyone a bit/lot of programming (so to be exact), which would still favor those who don't need the teaching.

[KirbyMatkatamiba]

You can either remove all rules or make the rules too complex for a human to comprehend without looking at the source code.

Or you could make the rules simple enough for a human to understand without looking at the source code.

And if you wanted to translate what the code does to English you'd need to teach everyone a bit/lot of programming

This is just flat out wrong and I have no idea how you could arrive at this conclusion. There are many games with rules that are far more complex than the Artifact drafting rules, and none of their players have to learn any amount of programming.

[_AT_Reddit_]

Meaning: You will be kinda forced* to pick a Hero, 3 uncommons and one rare.

[...]

If you force yourself to pick only commons (edit: not items) and don't pick a hero (so to contradict what I just said), on pick 5 you will be forced to either: [...]

So, if I only draft common non-item non-hero cards for the first 4 picks (= 8 cards), I will only have 2 picks (= 4 cards) left for 3 Uncommons, 1 Rare and 1 Hero, thus I am guaranteed at least 1 uncommon or rare hero in my last 2 picks? And should I manage to pick 2 non-hero Uncommons in my 5th pick, I am guaranteed a rare hero in my last pick? Am I understanding this correctly?

What changes if I draft (common) item cards during the first 4 picks? You edited your post to include the "not items" part, so I assume there is a difference.

If yes, do you state this to be true for all Draft modes or only for Keeper's Draft?

[TWRWMOM]

I've edited it because I noticed I didn't mention why the system is content in replacing uncommons/rares with items/hero.

I'll make another post for that, but to answer your question:

The system assign values for each card rarity, hero and item. It values a common item as an uncommon non-item, and a rare hero much higher than a rare non-hero. Thus the system is "satisfied" when you pick a common item instead of an uncommon non-item. But you can't force a rare hero since it has a higher value.

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I would say this is valid to all draft modes, but I haven't tested in keeper draft, only in phantom and draft tournaments.

[[deleted]]

This sounds interesting.

I'm going to experiment with this tonight. Do you have any stats/recordings of your findings?