Sparhawk Posted March 3, 2010 Share Posted March 3, 2010 It gives you the classic Mathematician answer. If anyone hasn't heard the joke it's pretty good ;). Link to comment Share on other sites More sharing options...
mowglie Posted April 20, 2010 Share Posted April 20, 2010 Oh you've got to be so careful with numbers, otherwise they get the better of you! How many wrecked/explodes results will the deffrolla inflict on a land raider? D6 S10 hits => 21/6 S10 hits => 21/18 penetrating hits => 21/54 = 0.388... wrecked/explodes results. That does not mean you kill a land raider 39% of the time! That means on average you will inflict 0.39 wrecked/explodes results to the land raider! Think about that. If that meant you killed the land raider ~39% of the time, then three deffrollas would kill the land raider ~127% of the time, which is obviously incorrect! That kind of maths is ok when you're talking about e.g. shooting small arms at tactical squads "I expect to kill 2.8 tactical marines by shooting with this squad". It's *not* ok when you're trying to figure out the probability of killing or not killing a single target. Bodacious2182 is correct. 39% is wrong. Maths is better than simulation, but only if you get the maths right! Let's do the maths right... What is the probability that at least one wrecked/explodes result will be caused by the deffrolla? The problem here is that the deffrolla might inflict more than one wrecked/explodes result. You can work that probability out directly, but its awkward. Much easier to find out the probability that the deffrolla *does not* cause any wrecked/explodes results, then take that away from 100% The probability that one S10 hit will *not* cause any wrecked/explodes results is 2/3 + (1/3 * 2/3) = 8/9 The probability that two S10 hits will *not* cause any wrecked/explodes results is 8/9 * 8/9 = 64/81 The probability that three S10 hits will *not* cause any wrecked/explodes results is 8/9 * 8/9 * 8/9 = 512/729 and so on... So, the probability that the deffrolla does *not* cause any wrecked/explodes results is:- 1/6 * the probability that one S10 hit does *not* cause any wrecked/explodes results plus 1/6 * the probability that two S10 hits do *not* cause any wrecked/explodes results and so on... that's:- (1/6 * 8/9) + (1/6 * (8/9)^2) + (1/6 * (8/9)^3) + ... + (1/6 * (8/9)^6) 1/6 * (8/9 + (8/9)^2 + (8/9)^3 + (8/9)^4 + (8/9)^5 + (8/9)^6) = 0.6756 The deffrolla has a ~67.56% chance to not cause any wrecked/explodes results. The deffrolla has a ~32.44% chance to cause at least one wrecked/explodes result (In addition there's a negligible chance that you'll cause five - or six if the raider has a multimelta - weapon destroyed/immobilised results and kill it that way, obviously if the land raider is already damaged, that probability goes up) Link to comment Share on other sites More sharing options...
Burningblood Posted April 20, 2010 Share Posted April 20, 2010 Just stumbled onto this. Though I lost the game (a very close loss to- made a moving mistake that cost me the draw I was going for), I had an imobilised LRC get rammed in the front by a deff rolla. It killed the deff rolla. It was pretty funny. Link to comment Share on other sites More sharing options...
Brother Valerius Posted April 21, 2010 Share Posted April 21, 2010 That does not mean you kill a land raider 39% of the time! That means on average you will inflict 0.39 wrecked/explodes results to the land raider! No, it does actually mean you kill a land raider 39% of the time... but you have to fight infinite battles to see that result. In the short term, it does not mean you have a 39% chance to kill the land raider over the course of the game. It does mean that you have a 39% chance to kill it each time, however. Basically, you're warning against the gambler's fallacy, which is good advice in the short term (which is all we deal with in practical situations). However, in the long (by which I mean infinite) term, the gambler's fallacy is actually true. Link to comment Share on other sites More sharing options...
Frosty the Pyro Posted April 21, 2010 Share Posted April 21, 2010 That does not mean you kill a land raider 39% of the time! That means on average you will inflict 0.39 wrecked/explodes results to the land raider! No, it does actually mean you kill a land raider 39% of the time... but you have to fight infinite battles to see that result. In the short term, it does not mean you have a 39% chance to kill the land raider over the course of the game. It does mean that you have a 39% chance to kill it each time, however. Basically, you're warning against the gambler's fallacy, which is good advice in the short term (which is all we deal with in practical situations). However, in the long (by which I mean infinite) term, the gambler's fallacy is actually true. no read the first page, there is a 32.436% chance to kill it each time, as stated teh .39 counts the chance of having 6 wreked destroyed results as 6 seperate success, when in fact it is mearly one success (as the target cannot become more exploded). Link to comment Share on other sites More sharing options...
mowglie Posted April 21, 2010 Share Posted April 21, 2010 That does not mean you kill a land raider 39% of the time! That means on average you will inflict 0.39 wrecked/explodes results to the land raider! No, it does actually mean you kill a land raider 39% of the time... but you have to fight infinite battles to see that result. In the short term, it does not mean you have a 39% chance to kill the land raider over the course of the game. It does mean that you have a 39% chance to kill it each time, however. As I explained in my post, if you could, say, hit a different land raider with each hit from the deffrolla, you'd on average kill 0.39 of them. That's not the case, though, as extra hits after the first "wrecked" result are wasted. Hence the lower probability. Nothing to do with the gamblers' fallacy. I despair at the constant misunderstanding of how probability works in gaming circles! Link to comment Share on other sites More sharing options...
thade Posted April 21, 2010 Share Posted April 21, 2010 Just stumbled onto this.Though I lost the game (a very close loss to- made a moving mistake that cost me the draw I was going for), I had an imobilised LRC get rammed in the front by a deff rolla. It killed the deff rolla. It was pretty funny. While I have enjoyed reading the math discourse in this threat, and it's all been very educational in the finer points of statistics (not my strongest field), *this* was my favorite reply. Much more like a Space Marine than a mathematician. :) Link to comment Share on other sites More sharing options...
mowglie Posted April 23, 2010 Share Posted April 23, 2010 It killed the deff rolla.It was pretty funny. I didn't think that was even possible? O.o Yeah, I'd have laughed pretty hard ^^ Link to comment Share on other sites More sharing options...
Hfran Morkai Posted April 23, 2010 Share Posted April 23, 2010 It killed the deff rolla.It was pretty funny. I didn't think that was even possible? O.o Yeah, I'd have laughed pretty hard ^^ Land Raiders are AV14 and a tank so that's a strength five hit off the bat, if the Ork Battlewagon were to move nine inches it could be glanced and twelve it could be penetrated, it's an unlikely scenario but it's possible. (Battlewagons aren't fast are they?) Link to comment Share on other sites More sharing options...
mowglie Posted April 23, 2010 Share Posted April 23, 2010 It killed the deff rolla.It was pretty funny. I didn't think that was even possible? O.o Yeah, I'd have laughed pretty hard ^^ Land Raiders are AV14 and a tank so that's a strength five hit off the bat, if the Ork Battlewagon were to move nine inches it could be glanced and twelve it could be penetrated, it's an unlikely scenario but it's possible. (Battlewagons aren't fast are they?) I don't have the book with me. Isn't the distance moved only added to the strength of the ramming tank? Link to comment Share on other sites More sharing options...
Hfran Morkai Posted April 23, 2010 Share Posted April 23, 2010 Isn't the distance moved only added to the strength of the ramming tank? Not as far as I'm aware, because it's driving into effectively a brick wall at however fast. Link to comment Share on other sites More sharing options...
Frosty the Pyro Posted April 23, 2010 Share Posted April 23, 2010 indeed, the speed is used for both the hit to the rammer and rammie Link to comment Share on other sites More sharing options...
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