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Cogito Ergo Run

Android: Netrunner Cogito Ergo Run Sieben

When to run on HQ

We’ve all probably seen this. The game ends, and the corp player yells: “I HAD 4 AGENDA CARDS IN MY HAND THE ENTIRE GAME!!!!!” Maybe the runner was distracted by shiny assets in remote servers, or the corporation bluffed his way through, but the game should have been an easy win for the runner. How was he supposed to know? Count cards.

Analysis:

Your typical corp deck has 49 cards and 9 agenda cards (20-21 points). The following analysis is based on this setup. If you believe that your corp opponent is running a much different agenda density, simply adjust your math.

A quick and dirty calculation says you should expect 1 in 5 cards to be agendas. So if the corp has drawn 25 cards, there will be about 5 somewhere on the table. If he’s only scored 1, and you haven’t scored anything, the other 4 are probably in his hand. Go for it.

In reality, there will be some variance in how many agenda cards the corp draws. We’ve all drawn a hand where we start with two agenda cards. It’s also common for corps to start with zero. The probability distribution is easily obtained through simulation. The spread is quantified below.

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Comments:

Agenda density is the proportion of agenda cards in the game. So if the corporation has drawn 20 cards, there is a 50% chance that he has (0.15)*(20) = 3 agenda cards somewhere in play.

The math is not reliable early game. There is a huge spread across the first 10 cards. On average, he'll have ~2 agendas, but he could have a lot more or a lot less. Do your own risk analysis.

The cases converge as the corporation draws more cards, so this estimation becomes more accurate as the game progresses. After about 25 cards, you can be fairly certain that he has drawn 5 +/- 1 agendas. If only one has been scored, there are probably a bunch in HQ!

Conclusion:

You should now have a fairly reliable way to estimate the number of agendas in the corp’s hand. Divide by the number of cards he’s holding, and get your probability for success. Don’t let the corp sit around with a hand full of agendas.
  • Amuk, accountdeleted, operdonos and 2 others like this


20 Comments

The chance of a high amount of agendas in the opening hand is even smaller when you take mulligans into account, because pretty much every 3+ agenda hand, and quite some 2 agenda hands are not worth keeping and will be redrawn, reducing the variance of agenda count of the opening hand (not that there is a high chance of drawing many in the first place).
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JeremyLarner
Feb 07 2013 11:30 AM
Very interesting article. I wonder (seeing as you're working probabilistically anyway) whether it might be better to do the analysis in terms of agenda points, rather than cards. I realise this only goes someway towards solving the problem of different agenda distributions, but it might give a more accurate estimate of the agenda points in HQ.
I've been asked by a reader to clarify what p10/p50/p90 is. Basically, there is a range of how many agendas the corp will draw. The lowest 10% of hands are represented by the p10 line. The median hand is represented by the p50 line. The 90th percentile is represented by the p90 line.

So there's only a 10% chance that the corp will be on the p90 or p10 line, meaning that the majority of games will between, close to p50.

Further reading: http://en.wikipedia....wiki/Percentile


The chance of a high amount of agendas in the opening hand is even smaller when you take mulligans into account, because pretty much every 3+ agenda hand, and quite some 2 agenda hands are not worth keeping and will be redrawn, reducing the variance of agenda count of the opening hand (not that there is a high chance of drawing many in the first place).

Correct. Notice that after 6 cards, the p90 case is that the corp has ~2 agendas. I agree there's a decent chance they'll mulligan this hand, but we can't be sure. The corp might also mulligan a hand with no agendas if he wants to score before icebreakers come out. This is muddy territory, so I didn't touch it.

If the p90 showed 3+ agendas I'd probably go re-simulate it. I still might, but I just woke up :P


Very interesting article. I wonder (seeing as you're working probabilistically anyway) whether it might be better to do the analysis in terms of agenda points, rather than cards. I realise this only goes someway towards solving the problem of different agenda distributions, but it might give a more accurate estimate of the agenda points in HQ.

I could rerun it for a standard case with 3/2/1 point agendas, but I'm not sure how much use you'd get out of it. The average agenda is always going to be 2 points, so the median line would stay the same shape.

It's also subjective for the runner if he prefers to run on a hand with 1 3-agenda card or 3 1-agenda cards. Noting of course, that the 1-agenda cards are primarily useful for things other than points!

If anyone else asks, I'll consider running simulations on different agenda point distributions.
Have you thought about modifying your assumption of a 49 card deck? How is the probability curves changed if I only run 3 point agendas in a 49card deck or in a 60 card deck? Also, How does running six 1 point agendas like Weyland corp affect the probabilty curves? in both a 49 or 60 card deck?

This is a very good start, but it could use some more depth!

Good job
Hah, you did start your own column after all Sieben :D

On the subject - Does "Corporate Draws" include inital 5 cards drawn? (If I read the graph correctly, it does not, but still want to make sure)

Also, try running the simulation with mulligans.
Assume Corp mulligans all hands with 3+ and 50% hands with 2 Agendas for simplicity.
I'd actually love seeing the numbers run on the first two Corporation tiers at both maximum and minimum. I can see a Jinteki Evolving Perfection running the baseline 45 as opposed to a Haas Bioroid Engineering the Future going to 54 sometimes, all depending on what's available.
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JeremyLarner
Feb 07 2013 03:33 PM

I could rerun it for a standard case with 3/2/1 point agendas, but I'm not sure how much use you'd get out of it. The average agenda is always going to be 2 points, so the median line would stay the same shape. It's also subjective for the runner if he prefers to run on a hand with 1 3-agenda card or 3 1-agenda cards. Noting of course, that the 1-agenda cards are primarily useful for things other than points! If anyone else asks, I'll consider running simulations on different agenda point distributions.

What I meant was, that looking for agenda cards is probably less useful than looking for agenda points. If I'm twenty draws in, and I've stolen a 2point agenda, and my opponent has scored 2 1-point agendas, it's pretty likely he has agenda in hand.

On the other hand, if he's scored 2 3point agenda, and I've stolen 1 3-pointer, running HQ is less likely to be fruitful. Yes, I could just use your graph, count up the points seen, and multiply by 2 to find an estimate of how many agenda points are likely in hand, but I suspect variance is lower if you model it in agenda points, rather than as cards. Maybe not though.

How is the probability curves changed if I only run 3 point agendas in a 49card deck

Like this: http://imgur.com/mJg...ARq80,vd8fGk7#3

or in a 60 card deck?

Like this: http://imgur.com/mJg...ARq80,vd8fGk7#0

Also, How does running six 1 point agendas like Weyland corp affect the probabilty curves? in both a 49

Like this: http://imgur.com/mJg...ARq80,vd8fGk7#2

or 60 card deck?

Like this: http://imgur.com/mJg...ARq80,vd8fGk7#1

This is a very good start, but it could use some more depth!

Good job

Thanks!

Hah, you did start your own column after all Sieben :D

On the subject - Does "Corporate Draws" include inital 5 cards drawn? (If I read the graph correctly, it does not, but still want to make sure)

It does not. And actually, the corp will have 6 cards on his starting turn, but the decision to mulligan is made after seeing only 5, and... it's complicated.

Also, try running the simulation with mulligans.
Assume Corp mulligans all hands with 3+ and 50% hands with 2 Agendas for simplicity.

According to your rules: http://i.imgur.com/CdWlK1Q.png

And the original without mulligans: http://i.imgur.com/M3lUgad.png

Basically it puts a discontinuity in the p90 case. As expected, the corp is less likely to have hella agendas in his hand.

What I meant was, that looking for agenda cards is probably less useful than looking for agenda points. If I'm twenty draws in, and I've stolen a 2point agenda, and my opponent has scored 2 1-point agendas, it's pretty likely he has agenda in hand.

On the other hand, if he's scored 2 3point agenda, and I've stolen 1 3-pointer, running HQ is less likely to be fruitful. Yes, I could just use your graph, count up the points seen, and multiply by 2 to find an estimate of how many agenda points are likely in hand, but I suspect variance is lower if you model it in agenda points, rather than as cards. Maybe not though.

There's a point after which you have to use your own judgment :P, especially when you start introducing conditional probabilities like a couple of 3-point agendas having been scored.

Running a bunch of 3 and 1 point agendas will introduce more variance than running flat 2 point agendas, because it will be possible for the first few agendas that come out to be worth a total of 9 points or 3 points.

I'd actually love seeing the numbers run on the first two Corporation tiers at both maximum and minimum. I can see a Jinteki Evolving Perfection running the baseline 45 as opposed to a Haas Bioroid Engineering the Future going to 54 sometimes, all depending on what's available.


10/45 agendas: http://imgur.com/6mlzszL,KRbKTFi#1

11/54 agendas: http://imgur.com/6mlzszL,KRbKTFi#0

All 2 pointers.
I did not realize everyone wanted so much detail. Don't say I didn't warn you about my next article...
    • Kennon, DubiousYak, wedgeex and 1 other like this

Basically it puts a discontinuity in the p90 case. As expected, the corp is less likely to have hella agendas in his hand.

Thanks!

I did not realize everyone wanted so much detail. Don't say I didn't warn you about my next article...


Looking forward to it =P
Thanks for the data. I guess you can conclude that deck size does not affect agenda density. Also, one can say that 3 point agenda decks have more constant agenda density @ p50 than decks that have at least six 1 point agendas. Interesting...any more thoughts?
"Running a bunch of 3 and 1 point agendas will introduce more variance than running flat 2 point agendas, because it will be possible for the first few agendas that come out to be worth a total of 9 points or 3 points"

Data Please! Feed me!

"Running a bunch of 3 and 1 point agendas will introduce more variance than running flat 2 point agendas, because it will be possible for the first few agendas that come out to be worth a total of 9 points or 3 points"

Data Please! Feed me!

Since two people asked...

All 2 pointers: http://i.imgur.com/UW5Iqx6.png
Standard mix of 2 and 3 pointers: http://i.imgur.com/ygBgvbK.png
Many 1 pointers - typical weyland setup: http://i.imgur.com/nytXAyn.png

Let me know what you get out of this. I see the utility in knowing the theory behind card density, spread, etc, but at this point the actual numbers are lost on me.
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ironchefzod
Feb 07 2013 10:43 PM
I think the level of detail is perfect for a ballpark expected agenda count. I had been using 1 in 5 cards for agenda estimates, but it's pretty cool to know p10 is about 1 in 4 and p90 is about 1 in 8.

Nice article, keep em coming. That goes for TechTalk and Datapack Card Reviews too. Some of the last couple comment threads may have had some negative comments, but I've always appreciated the work people put into these articles.

What I meant was, that looking for agenda cards is probably less useful than looking for agenda points. If I'm twenty draws in, and I've stolen a 2point agenda, and my opponent has scored 2 1-point agendas, it's pretty likely he has agenda in hand.

On the other hand, if he's scored 2 3point agenda, and I've stolen 1 3-pointer, running HQ is less likely to be fruitful. Yes, I could just use your graph, count up the points seen, and multiply by 2 to find an estimate of how many agenda points are likely in hand, but I suspect variance is lower if you model it in agenda points, rather than as cards. Maybe not though.


Thinking about points instead of cards actually makes it simpler to understand, and easier to adapt to someone's actual play. I haven't completely checked my reasoning here, so if you spot something you disagree with, please say so.

When you approach the problem from a points standpoint, you know the expected agenda value of every card: it's agenda points/deck size, usually something like 20/49, so let's say 0.4 agenda points per card. So if your opponent has drawn 10 cards, you can expect those cards to hold 4 agenda points (on average). If you wanted to be completely accurate, you could recalculate whenever you see a new card, to unseen agenda points/amount of unseen cards.

This is actually a more useful way to think about it than amount of agendas, because you can try to judge how those expected agenda points are divided over agendas on a per deck, per opponent basis, and adjust to the agendas you've already seen. If most 3-pointers are already gone or do not fit the deck, 4 expected agenda points probably means that the corp is holding at least two agendas. In the end it's all statistics, so in one game this won't guarantee anything, but in the long run I think this is the most informed way to think about it.
What might be useful is to keep a dice at hand, and count up every time the corp draws a card, to have a handy reference of how many cards are gone, instead of having to count up table, hand and archive cards :)

If most 3-pointers are already gone or do not fit the deck, 4 expected agenda points probably means that the corp is holding at least two agendas. In the end it's all statistics, so in one game this won't guarantee anything, but in the long run I think this is the most informed way to think about it.

This only works if you are only concerned with the "average" case. In reality, the spread or variance is only captured when you factor in *both* the number of agenda cards, and their point density. So looking at point-density alone is insufficient to optimize your heuristics.

But, at that level of detail, you're probably way beyond the point where additional accuracy will improve your gameplay :D


What might be useful is to keep a dice at hand, and count up every time the corp draws a card, to have a handy reference of how many cards are gone, instead of having to count up table, hand and archive cards :)

Yes. I forgot to remind people that they don't have to actually keep count of cards. It says in the netrunner rules that you can always count the number of cards in a deck, discard pile, and hand.

I use http://www.amazon.co...onic counter e2 When I'm feeling OC

I do use dice, but I pack 4. I set one down every time my opponent takes an action. When I need to access a random card, I roll the appropriate dice. Again, OC.

This only works if you are only concerned with the "average" case. In reality, the spread or variance is only captured when you factor in *both* the number of agenda cards, and their point density. So looking at point-density alone is insufficient to optimize your heuristics.

But, at that level of detail, you're probably way beyond the point where additional accuracy will improve your gameplay :D


the predictions for the average case are the same from both perspectives, though indeed I have not calculated how the actual variance relies on over how many cards those points are really distributed, partly because I'm lazy, partly because there's just not much to be gained by such precision. Personally I find counting 0.4 agenda points per card, and keeping in mind that this estimate is less reliable when my opponent runs many high-pointers, and more reliable when they run many low-pointers enough to help making informed decisions, without being too much effort. In the end the expected agenda points/cards are only part of the information you use to make final decisions. The behavior of the Corp plays a major role as well. Counting cards is just a way to better be able to interpret that behavior.
    • Sieben likes this
No matter how unlikely the outlier, don't take chances. Learnt this lesson today from having 3 Priority Requisitions pulled from my R&D on my 5th turn. I only did 5x3 = 15 clicks, drew 5 cards. Seriously. That's with just 1 Maker's eye. The last 2 were pulled next to each other on the runner's last 2 clicks. WTF.
4 iterations of a 6 pile shuffle, cutting at a random place inbetween iterations randomizes the deck.

Yes, this is specific for netrunner. I simulated it using a typical distribution of 1/2/3 copies of each card.