Help - Search - Members - Calendar
Full Version: Probability and Statistics
Dumpshock Forums > Discussion > Shadowrun
Pages: 1, 2
Crimsondude 2.0
Now I have to look at your references.
blakkie
QUOTE (Jon Szeto @ May 14 2005, 05:20 PM)
QUOTE (Crimsondude 2.0 @ May 13 2005, 03:08 AM)
I'd rather have 1 guy with a degree in Stats run a game line than a dozen people with doctorates in any liberal arts.

How about a BS in engineering physics, with an additional four years of work experience in quality engineering, statistical process control, and Six Sigma?

That kinda worries me. If SR4 makes it to 3.4 defects per million opportunities i will become completely perplexed and disorientated from the disbelief that it is an RPG. wink.gif

P.S. Your university transcripts would help.
Ellery
QUOTE
How about a BS in engineering physics, with an additional four years of work experience in quality engineering, statistical process control, and Six Sigma?
Cool. Hopefully this means, in SR4, that a world expert in parachuting won't die half the time he tries a HALO jump; that if you're somewhat inexperienced and shooting someone in the rain in dim light, it still is harder to hit your target if they are running (but not impossible); and that a cyberized Hulk Hogan doesn't often lose an arm-wrestling match with Michael Jordan. And if my hopes are dashed, maybe you at least will be able to join me in telling the other developers, "I told you so!"
blakkie
You do realize that HALO jumps are very dangerous and have a high injury rate for those fully trained in the technique? Add in very uneven and unknown terrain and other factors such as poor visibility and it should be deadly serious for the untrained to attempt (by untrained i mean some training in parachuting, but not in HALO). Maybe not 50% fatality (what modifiers, Skill, and Body do you see that at?), but still very dangerous.

That said it would be good to have a lower fatality to injury ratio than I've seen out of SR3 HALOs.
Shockwave_IIc
QUOTE (Ellery)
Hopefully this means, in SR4, that a world expert in parachuting won't die half the time he tries a HALO jump;

Sorry i had a giggle when i read that.

This might be of use to you.
blakkie
This is what happens when you try to jump at night in a city that is prone to gusts coming out of the nearby mountains:

http://www.macleans.ca/topstories/sports/a...8_103870_103870

EDIT: BTW i think i read in a later article that he is expected to be in hospital for a month or few with busted up hips and other bones. By SR standards that's about 9ish boxes. He was alert enough to make a phone call but wasn't going anywhere fast under his own power (something that SR doesn't really model).

That article says only 80 deaths in the last 20ish years. Given the number of jumps that's fairly low fatality percentage. However i suspect that the vast majorit, if not all of those people had damn good information beforehand about the height of the jump, typical and current wind conditions, etc.
Jon Szeto
QUOTE (blakkie)
That kinda worries me. If SR4 makes it to 3.4 defects per million opportunities i will become completely perplexed and disorientated from the disbelief that it is an RPG. wink.gif

IMHO the entire game industry is about 1.5 Sigma at best, so I have to wonder if there are enough black belts in the entire world to get any game system to 6 sigma. wink.gif
FrostyNSO
If they're going to include parachuting rules (including HALO), please don't forget the forgetten stepchild of parachuting: The HAHO jump.
Charon
Yes. It wouldn't be Shadowrun without it.
Kagetenshi
And for your runner who has ingested too much helium, we also need rules for LAHO.

~J
Jrayjoker
Why is it that every topic I start degenerates into bad puns sooner or later?
Jrayjoker
QUOTE (Jon Szeto)
QUOTE (Crimsondude 2.0 @ May 13 2005, 03:08 AM)
I'd rather have 1 guy with a degree in Stats run a game line than a dozen people with doctorates in any liberal arts.

How about a BS in engineering physics, with an additional four years of work experience in quality engineering, statistical process control, and Six Sigma?

I am cool with you bein' all smart and stuff, but...

I have an MS in structural Engineering and a BA in physics, but I can't do stats for squat.

Your cred is strong for me if you say you understand it and have applied it to the stuff you have worked on, but what about the 75,347,193 others who have contributed to SR4 who can't find (n-1) with a map and a sherpa?
Charon
QUOTE (Jrayjoker)
Why is it that every topic I start degenerates into bad puns sooner or later?

Why shouldn't they degenerate? All the others do.

Do you think you're the chosen one who will bring balance to the board?

QUOTE (Jrayjoker)
Your cred is strong for me if you say you understand it and have applied it to the stuff you have worked on, but what about the 75,347,193 others who have contributed to SR4 who can't find (n-1) with a map and a sherpa?


It's hardly necessary for everyone to be fluent with stats on the team. As long as they understand the necessary explanations of the person(s) that do(es).

I doubt the marketing people in Fanpro truly understand what the guys in finance are doing either, yet somehow the business ends up being run.
Wireknight
QUOTE (blakkie)
You do realize that HALO jumps are very dangerous and have a high injury rate for those fully trained in the technique? Add in very uneven and unknown terrain and other factors such as poor visibility and it should be deadly serious for the untrained to attempt (by untrained i mean some training in parachuting, but not in HALO). Maybe not 50% fatality (what modifiers, Skill, and Body do you see that at?), but still very dangerous.

That said it would be good to have a lower fatality to injury ratio than I've seen out of SR3 HALOs.

So, you're saying that the SR "you die a statistically large amount of the time you attempt a HALO Jump" mechanic is realistic... but then you follow up by about-facing and agreeing with Ellery that it's too highly lethal.

Does not compute.
blakkie
QUOTE (Wireknight @ May 16 2005, 04:14 AM)
QUOTE (blakkie @ May 15 2005, 12:25 AM)
You do realize that HALO jumps are very dangerous and have a high injury rate for those fully trained in the technique?  Add in very uneven and unknown terrain and other factors such as poor visibility and it should be deadly serious for the untrained to attempt (by untrained i mean some training in parachuting, but not in HALO). Maybe not 50% fatality (what modifiers, Skill, and Body do you see that at?), but still very dangerous.

That said it would be good to have a lower fatality to injury ratio than I've seen out of SR3 HALOs.

So, you're saying that the SR "you die a statistically large amount of the time you attempt a HALO Jump" mechanic is realistic... but then you follow up by about-facing and agreeing with Ellery that it's too highly lethal.

Does not compute.

It doesn't compute because you seem to have misunderstood. What i said was that to some extent high injury rates make sense, but the really high fatality rates don't. Injury is not nessasarily fatality.

P.S. SR isn't a simulation, it's a game. As pointed out many times and in many ways the area of firearms is flat out wacked in RL terms. However if you did rework firearms and combat to match, for example, RL hit/miss ratios would it still be fun?
Jrayjoker
QUOTE (Charon)
QUOTE (Jrayjoker @ May 15 2005, 10:23 PM)
Why is it that every topic I start degenerates into bad puns sooner or later?

Why shouldn't they degenerate? All the others do.

Do you think you're the chosen one who will bring balance to the board?

QUOTE (Jrayjoker)
Your cred is strong for me if you say you understand it and have applied it to the stuff you have worked on, but what about the 75,347,193 others who have contributed to SR4 who can't find (n-1) with a map and a sherpa?


It's hardly necessary for everyone to be fluent with stats on the team. As long as they understand the necessary explanations of the person(s) that do(es).

I doubt the marketing people in Fanpro truly understand what the guys in finance are doing either, yet somehow the business ends up being run.

Point taken, and understood. I was trying to be funny, but apparently missed.

I was kind of hoping I was the chosen one, but I guess I'll have to wait. smile.gif

Point #2 - agreed, but I still need to see his transcripts wink.gif
The White Dwarf
Claiming you have to see someones transcripts to qualify them to make a game that you want to buy is kinda being self-important. They dont need your approval to do it, and they said they were keeping this in mind. Thats good enough for me.
Kagetenshi
On the contrary. Claiming you'd need to see it to qualify them to make a game period would be, but one may set the bar at which they spend their money at any level they choose.

~J
Kagetenshi
Bugger all.

~J
Ellery
Having a transcript doesn't necessarily mean that you're good at everything that the average person with that transcript is good at.

Also, having the capability to do something doesn't mean that you actually do it.

I'd rather have HS dropouts checking the probabilities carefully and making changes accordingly, than a Professor of Applied Statistics writing the game without paying any attention to the statistics. Unfortunately, the average HS dropout is not able to check probabilities (although some certainly can--mathematics is open to everyone).

So I'm being pretty demanding here: I'd like at least one person who could do the job, and I'd also like them to do it!
mfb
she asks too much!
blakkie
QUOTE (The White Dwarf @ May 16 2005, 04:07 PM)
Claiming you have to see someones transcripts to qualify them to make a game that you want to buy is kinda being self-important.

Yes, that's the joke! smile.gif I never really expected them.
blakkie
Another one bites the dust, or the deck as it were. But that sounds like a Rule of 1 roll. It got caught on part of the building and pulled it off him? I wonder if it was the spikes or whatever they have to try keep people from climbing out of the deck to jump.
Jrayjoker
QUOTE (The White Dwarf)
Claiming you have to see someones transcripts to qualify them to make a game that you want to buy is kinda being self-important. They dont need your approval to do it, and they said they were keeping this in mind. Thats good enough for me.

I wasn't claiming they couldn't "make a game", just that the application of probability and statistics by a lay person is not a simple thing to do correctly. And please note the wink.gif. I was making a funny and disarming any potential hurt feelings by the use of a cutesy wootsey emoticon.

Vetting someone based on their transcript is one way we "raise the bar" as Kage said.

One of the best mathematicians I know is self-taught as a hobby, so I am not disparaging anyone's credibility with regard to formal education or lack thereof. I will take it on faith that someone is doing a good check if they say they are.

If I find that the numbers don't play out after they have been analysed I will hunt all of them down and serve them 40 lashes with a wet noodle for their lies.

As Twain said, "There are three kinds of lies: Lies, Damn Lies, and Statistics."
Jrayjoker
QUOTE (blakkie)
Another one bites the dust, or the deck as it were. But that sounds like a Rule of 1 roll. It got caught on part of the building and pulled it off him? I wonder if it was the spikes or whatever they have to try keep people from climbing out of the deck to jump.

Ugh. I hope he didn't suffer.

Perhaps the SR ratios of death to injury for HALO and base jumping are merely exaggerated.
mfb
that doesn't fix the rules for regular parachuting. i mean, for chrissake, why do you default to body!?
blakkie
QUOTE (mfb)
that doesn't fix the rules for regular parachuting. i mean, for chrissake, why do you default to body!?

Because it was grouped under Athletics. That Athletics is linked to Body i always found odd too. But which skill links to which attribute is an old, old saw.

P.S. Is it just me, or does the concept of "Defaulting" (doing it with no training) parachuting in RL just not seem like a good idea?
Nikoli
Jumping out of a perfectly good airplane doesn't seem like a good idea either.
mfb
depending on what you think skill 1 represents, people do it all the time. moreover, the skill of the guy pulling the ripcord doesn't have a lot of bearing on whether or not his parachute deploys, as the rules suggest. the rigger that packed the 'chute ought to have some dice in there somewhere.
Req
QUOTE (Nikoli)
Jumping out of a perfectly good airplane doesn't seem like a good idea either.

Don't knock it 'till ya try it. 'Course, when I went, I had a skill of zero. Amazing I survived!
mfb
you must have used hand of god.
Kagetenshi
You find it amazing he survived. I say: Maybe he didn't!

~J
Req
QUOTE (Kagetenshi)
You find it amazing he survived. I say: Maybe he didn't!

Damn. They're on to me.
Jrayjoker
Isn't it a little early for Shedim?
Nythrun
The examples of skill use listed in pretty much all of SR3 wend from statistically implausible to hellbound snowmen: flipping open Rigger 3 Revised randomly to page 83 yields Josie throwing eight dice at TN5 (six successes), TN7 (four successes), and TN8 (four successes) to reduce footprint. Now this isn't as egregious as the samples in, say, Magic in the Shadows, base TNs can start at 12 and where five dice routinely provide a handful of successes at TNs of 9 or more (and maybe "a few" task pool dice in the R3R example actually means "all three that you can get" rather than "two") - but this passage isn't convincingly indicative of statistical analysis. And I do realize that skill tests in examples need to be resolved exempli gratia, which is fine - but it's also reasonable to wonder why example tests demand fudging so very often, and surmise that maybe someone wasn't doing their homework.

Of course, the results of a rigger's Reducing Footprint test apparently have infinite duration and the test only has to be made once at chargen anyway, rendering the rules for it irrelevant and dysfunctional. That, however, is not a probablistic objection.

None of which, by the way, is intended to single out SR3 for mathematical scolding; D20 and White Wolf are no better and often worse. If, however, SR4 intends to sanity check the requirements for each category of things you can do, then I have to ask:

Really?
By Gencon?

Because it's a claim made in advertising often, and in practice never.

Let X equal the number of dice rolled
Let N equal the desired number of successes
Let C equal the number of possible combinations of N items in a set of X items

C{[4^(X-N)]/[6^X]} isn't a lot to solve.
mfb
yeah, i agree. the autofire example with Wedge was another questionable example, as i recall. i hope they use more realistic examples in SR4.
blakkie
Hehe, i always envisioned the die roller in those examples as squirming in pain as the horseshoe pinched his lower colon. smile.gif Or they had a pile of Karma Pool available so they could reroll a lot, and that the rerolls simply weren't mentioned.

Note: In fairness for some of those examples the extra successes were good to have to show different aspects of the rules that one or two successes would not. They could have increased the number of dice rolled, but then we'd likely be going "WTF are they getting that many dice from?"
mfb
fudging the numbers a little bit is okay. but check out the ECM example in SR3: 10 dice, TN 8: 4 succs. 8 dice, TN 3: 2 succs. what the hell?
blakkie
Maybe the 10 dice were rolled behind the screen? They seem to mysteriously roll better back there sometimes. vegm.gif

I hear and agree with what you are laying down though. It certainly would be a nice polish to have the examples constructed so that the majority aren't at the extremes of chance. Sorry i didn't make that clear.
mfb
personally, i wouldn't be adverse to showing examples that only use strictly average rolls. if you can't get your example to work at some minimal level with average rolls, well, maybe you should take a good, hard look at the mechanic you're trying to introduce.
blakkie
The problem with strictly average rolls is showing off some of the extremes of the system, such as when extra rules kick in past a certain number of successes. The Rule of 1's, a relatively rare condition, is also such a place to use rare rolls.

EDIT: But that's a good suggestion you make, that if a rare roll is needed to activate it you should reevaluate the rule and the underly mechanism that requires the rule.

Generally you also want to have as few matching numbers in the example as possible, unless there is something specific that needs the numbers the same.

An example:
For an opposed PC #1 rolling A dice gets B successes; PC #2 rolling X dice gets Y successes.

The numbers assigned to A, B, X, and Y should all be different numbers unless you want to show what happens when PC#1 and PC#2 roll the same number of successes (B and Y). This usually makes it easier to understand the example as matching numbers can become red herrings.

EDIT: Notice that the example you mention made that mistake. The TN of one character is the number of dice of the other character, but there is no meaning behind that match.

If you allow a bit of leeway it becomes easier to find a nice mix of numbers to fit that condition. A guideline could be "if a roll is lucky enough that it would enter your personal gaming story lore, good or bad, and the example can be clear without that particular roll, then change it".
mfb
right, exactly. average rolls should be used unless you're specifically trying to show what happens with extremely high or extremely low rolls. the non-matching numbers is a nice way to reduce initial confusion as well, simply because of the way people's memory works--if you see two 8s in an example, you're likely to later group them together and get things mixed up.
Ellery
I am tempted to mention that having a little variability around the average produces better examples yet. But that's the second step.

The first step should be to make examples with very close to average rolls. If they work, great! If they don't, fix the rule!

Then in some cases you might want to introduce a little more variability to better reflect that dice are variable.
Nythrun
"...characters should assense a spell and try to learn its force before attempting to dispel it. (SR3, 184)"

That's sound advice, no one wants to kill their PC trying to dispel. And in the best case scenario of a PC with Aura Reading 6 as well as Intelligence 6, the "prerequisite" assensing might garner necessary five successes as much as half of the time. For a more typical PC, however, those five successes will occur only one time in sixty-seven - which is not quite "seven impossible things before breakfast" but does mean that most characters are recommended to never attempt any dispelling.

One possibility is that the Third Edition intended dispelling to be a marginalized technique completely ignored in most games, which is the situation that obtains. I will take a leap of faith here and assume that there's consensus as to why dispelling is generally a poor stratagem; arguments thereto may be left undredged for concision's sake.

But another possibility is that assensing a spell's force is a little more difficult than the writer of that first quoted passage remembered, and perhaps four successes would have been better. Without a typical case example, it's not easy to say which possibility is more correct.
Jrayjoker
QUOTE (Ellery @ May 18 2005, 07:05 PM)
I am tempted to mention that having a little variability around the average produces better examples yet.  But that's the second step.

The first step should be to make examples with very close to average rolls.  If they work, great!  If they don't, fix the rule!

Then in some cases you might want to introduce a little more variability to better reflect that dice are variable.

Also, the rigerous analysis of average rolls are needed to ensure that basic tests across different disciplines are balanced in such a way that there are similar likelihoods of success.

That looks awkwards, so let me rephrase it.

A person with skill 6 in pistols shooting a motionless target at short range with a smartgun II cyber-sytem (TN 2), should have the same probability of hitting their target (assuming no dodge) as the decker trying to browse for a file on Green 6 8/6/7/6/8 host with a rating 4 browse utility (TN 2) has to find the file.

Similarly for mages and riggers, etc.
Ellery
QUOTE (Jrayjoker)
Analysis of average rolls are needed to ensure that basic tests across different disciplines are balanced in such a way that there are similar likelihoods of success.
Only within reason. Some basic skills may accomplish less than others, and some disciplines may be less reliable than others. I don't really see a problem with that until it gets to the point where there is no compelling reason to be a decker (or not to be). But the relative balance should be an intentional thing, and not an accident of not realizing what the probabilities would be.
Charon
QUOTE (Jrayjoker @ May 20 2005, 01:30 PM)
Also, the rigerous analysis of average rolls are needed to ensure that basic tests across different disciplines are balanced in such a way that there are similar likelihoods of success.

...

A person with skill 6 in pistols shooting a motionless target at short range with a smartgun II cyber-sytem (TN 2), should have the same probability of hitting their target (assuming no dodge) as the decker trying to browse for a file on Green 6 8/6/7/6/8 host with a rating 4 browse utility (TN 2) has to find the file.


I don't see where you are going with this.

Obviously, rolling 6 dice against TN 2 while shooting at someone gives you the same odds of success as rolling 6 dice against TN 2 while decking. It doesn't take a "rigorous analysis of average roll across different disciplines" to see that. Same TN + same number of dice = same odds.

Similarly, whenever rolling 8 dice and requiring 3 success in SR4, you'll have the same odds of success no matter what that activity is.

The real question is, what is a task that requires 3 success when shooting? Hacking? Driving? Casting a spell? Some of these can be answered by comparing to real life odds while other are pure design choices. How hard should decking or magic be? And what is the average number of dice rolled for these activities? This is where things could get wacky between editions. Will frying the brain of an average guard with a mana bolt be roughly as difficult in SR4 as it was in SR3? I'm guessing the extremes will change. A Will 6 probably won't be more than twice as good as a Will of 5 to resist mana spells as it is in SR3, but what is important is if the overall, average, difficulty are roughly similar.
Ellery
The extremes can matter, though. If will 6 is only 20% better than will 5, instead of twice as good, it kind of cuts down on the possibility of having someone in a group of mundanes who is really magic resistant. You'd have to implement that other ways.

It can be a big change to the way a game is run, especially if the PC has made his career around being the one with Will 6 who takes down the spellcasters.
Charon
QUOTE (Ellery @ May 20 2005, 07:04 PM)
The extremes can matter, though.  If will 6 is only 20% better than will 5, instead of twice as good, it kind of cuts down on the possibility of having someone in a group of mundanes who is really magic resistant.  You'd have to implement that other ways.

It seems obvious to me that this state of affair is just a byproduct of the system and not a deliberate decision of the designer. I see no need to maintain it. The difference between 5 and 6 and then between 6 and 7 for spell resistance purpose is something to poke joke at, not preserve as an important part of SR. I'd welcome a more linear progression, myself.
Ellery
QUOTE
he difference between 5 and 6 and then between 6 and 7 for spell resistance purpose is something to poke joke at, not preserve as an important part of SR.
Oh, I agree. The scaling is hardly ideal. What is perhaps wanted is a way to make certain mudane individuals substantially harder to affect than average. Otherwise magic becomes hard to balance--a little too much power and nobody can resist a mage; a little too little and nobody has to worry about a mage.

Without attention, the default will be for mages to affect most people more equally than they used to. Maybe this is a good thing, but either way, it should be something done intentionally. Otherwise you'll balance things thinking, "Hey, W6, this guy is great against magicians!" and then he'll be knocked out with a stunball right along with everyone else.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Dumpshock Forums © 2001-2012