Hmm, doesn't (1- P(defender win (2 turns)) already include the defender having failed at T1?

I´m going for (Probability of a first turn win) + [Probability of results that allow a second turn] * (Probability of 2nd turn win).

So the chance of being detected has to be used for calculation in both turn 1 and 2. Huh, I think. Does someone else have an idea or corrections?

Well, I just managed to figure out one thing, my way of calculating extended tests is BS:

By my math, the chance to roll one die twice and score a hit on the second attempt is P(0 hits with one die) * P(>= 1 hits with two dice). But that also includes the impossible event "roll 0 hits on the first try and a total of two hits on two rolls". Back to the drawing board, stupid...

I still want to know what one learns in a "statics" class.

I assume you learn about the physics of unmoving objects. So you can later advance into the "happy" math of dynamics.

Got fed up with thinking about formulas and picked up on Murray's advice again: Just simulate the damn thing with enough iterations. Matlab code for those interested, it should be readable if you know a bit about any programming language (and no, Matlab does not have ++ or += operators):



As an example output I present the chance of hacking a Security account at a R. 3 node running Analyze 3, as function of the attacker's DP and Stealth rating:
http://postimage.org/image/atkk35isx/full/ (better image host now)

This post has been edited by Sengir: Dec 6 2012, 12:57 PM

Awesome Sengir, Thanks. (IMG:style_emoticons/default/smile.gif)

I use to be a TA for this class. It's an engineering class that focuses upon forces and moments (torques for lay people) of stationary structures or situations. Things like the wind loading on a billboard, a roof supporting weight from snow or other distributed loads based upon its design, etc. It's usually a end of first year or beginning of second year course for mechanical and civil engineers. Hope that helps.

P.S. sorry, it's not about static electricity or anything cool like that.

That's very interesting. I hadn't thought yoru Stealth program had more to do with your chance o success, than your die pool.

Is that "regardless of number of rolls needed", or what?

Well, I imagine the Numbers change when performing a Slow Hack. IIRC, the initial query was based upon a Hack-on-the-Fly Attempt.

So a hacker with Stealth 6 and a 14-16 DP vs. a Rating 3 node with Analyze 3 (DP 6) has ~10% chance of being detected when hacking-on-the-fly?

It would be interesting how this graph scales when considering that a starting technomancer could get stealth up to 12.

For a Security account, mind you.

Another interesting observation: If you do not apply the cumulative -1 to the node's DP, the result looks like this. A remarkably small difference (at least far smaller than I expected) for hackers rolling twelve or more dice.

More graphs for various Ratings and account levels (User/Security/Admin) by tomorrow, I'll hit the bed now.

Probably the simplest way to do it directly - ie, deriving the actual probability rather than approximating it with an experiment - would be to use the negative binomial distribution. Negative binomials give you the distribution of the number of total dice rolled before you have X successes. If you have a dicepool of d, then the sum of the negative binomial distribution from (s-1)d+1 to sd gives you the probability that you get to X successes after precisely s tests (without the -1 per cumulative test), or from (s-1)d-(s-1)s/2+1 to (s-1)d-(s-1)s/2+1+d-s if you are using the -1 per cumulative test (with the remaining probability meaning you never reach it). At this point you have a probability distribution (albeit a mildly ugly one) for the probability of taking exactly s tries to get to X successes, so you can do a simple conditional probability summation to get to your answer.

This does, however, ignore glitches which do make things a bit of a nuisance to calculate.

As promised, lots of colorful lines:

• Rating 1 User | Security | Admin
  
• Rating 2 User | Security | Admin
  
• Rating 3 User | Security | Admin
  
• Rating 4 User | Security | Admin
  
• Rating 5 User | Security | Admin
  
• Rating 6 User | Security | Admin
  
• And for a more humbling experience, Rating 10 User | Security | Admin

Which pretty much proves that the Hacker in a Box (rolling 6 Dice) hacking Rating 2 Comlinks in the Quad for 5 (IMG:style_emoticons/default/nuyen.gif) each will rarely, if ever, really succeed at its mission. Thanks Sengir. Pretty much what I expected. (IMG:style_emoticons/default/smile.gif)

Depends...if you want to use it as a banking trojan (I assume you were referring to that discussion) it would very rarely succeed, since that requires Admin access. On the other hand, getting User access to to read somebody's stuff will succeed in ~75% of all cases, so a R. 2 commlink is pretty much an open book.

Talking about the Trojan for banking that money.
And from your graph, 6 dice vs. 6 Dice is not 75% (since you used a Target Rating 3 Device)... or did I read that wrong? Looks like just above 30% to me.

Sorry, I've been out for a few days. It's about torque, forces, and trigonometry. Significantly different than the probability stuff I expected.

For Rating 3 you are reading correctly, but you were talking about "hacking Rating 2 Comlinks in the Quad" (IMG:style_emoticons/default/wink.gif)

Btw, thanks for weighting in Umaro, although I'm happy with the results I have.

Good... just wanted to make sure I was reading the chart correctly.
Awesome work.

IIRC, one has to get admin accounts on commlinks.

Basic Nonmoving Engineering - Forces & displacements for objects like beams, trusses, and the like.

Yes, since no other accounts exist on a comlink by default.

What is this so? That's awesome! That solves so much. Can someone give me background on this?