Scatter dice and math hammer

[Brother-Chaplain Gaius]

Myself and the scatter dice have never had a great relationship, ever. and I'm wondering exactly what are the odds to hit/miss on a scatter? assuming we're using BS 4

 

Knowing the chances will help me decide what to give my new devastators. thanks guys!

[Commander Sasha]

Assuming you are talking about a single model:

Large blast

Direct hit, 1/3

Miss, deviation of 3 hits; 4+ misses ie 2d6=8+; misses 15/36; hits 21/36 =7/12

Probability of hit= 1/3 + 2/3*(7/12) = 28/36 = 0.777

 

Small blast

Direct hit, 1/3

Miss, deviation of 2 hits; 3+ misses ie 2d6=7+; misses 21/36; hits 15/36 =5/12

Probability of hit= 1/3 + 2/3*(5/12) = 22/36 = 0.611

 

Hope my maths is right, happy to be outclassed!

[glsn]

Aim at the center of the group. A third will hit what you aim at, a third will hit the things beside what you aim at, and a third will hit your own guys. All told, I love the thunderfire cannon.

[Chengar Qordath]

As a general rule, scatter dice can't be perfectly mathhammered since a lot of their success rate depends on the disposiiton of the enemy unit you are targetting, which is different every single time you shoot. There have been times when I rolled max scatter and actually did more damage than if the shot had been on target, or had just a tiny amount of scatter be enough to result in a total miss.

[Brother-Chaplain Gaius]

thx for the replis. and good math cmmdr sasha.

 

perhaps i was too vague, I know scatter dice depends on some variables that cannot be determined, unless we were basing it off a single game/ terrain layout. But in general I was referring to small blast bs4, being fired into the middle of say a tac squad

[Justicar Valius]

Well for no scatter you have 1/3 + (4/6 [you miss on sactter dice]* 1/6 [probability of rolling a 4 or less])= 4/9

to scatter 2 inches or less (pretty much what you need vs 10 tac marines) is 1/3 + (4/6* 15/36)= 1/3+30/109 =0.61 (2.d.p)

 

That help?

[Brother-Chaplain Gaius]

If I'm reading it correctly, yes. its 61% chance for direct hit? doesnt sound right to me

 

If i' not reading it correctly sorry please be patient I was never good at math and dropped it as soon as i could in school

[Jackelope King]

61% is the probability that a blast will scatter less than 2 inches from the initial target, whether because you rolled a "hit" on the scatter die, or the total scatter was 6 or less. And I don't have it with me to measure, but I think the small blast is 2" radius?

[Sparhawk]

I thought the radius was 1.5", mainly because I thought our blast templates were 3" and 5".

[Chengar Qordath]

I thought the radius was 1.5", mainly because I thought our blast templates were 3" and 5".

Correct. However, as I recall with a 2" deviation a small blast template will still cover part of the model it was centered over.

[Koremu]

That may not be the only question concerning the probabilities with scatter dice though. What is the probability that a Demolisher Siege Cannon will hit a Monolith with the Monolith filling the centre hole of the Large Blast Template if the initial shot is exactly centred on the centre of the target?

[Brother-Chaplain Gaius]

61% is the probability that a blast will scatter less than 2 inches from the initial target, whether because you rolled a "hit" on the scatter die, or the total scatter was 6 or less. And I don't have it with me to measure, but I think the small blast is 2" radius?

ok thanks, and the small blast is 3"

[Xeonic]

And at least once out of that 39% chance to scatter off the target unit I've rolled boxcars and had a plasma cannon shot thus drift 8" and immobilze my own predator. ;)

 

Mathhammer tells me further that rolling boxcars was a 1 in 36 chance(something like less than 3%), and the scatter dice rolling the arrow in the right direction when actually there weren't any other friendly targets in range is well, a really really low chance. Still the most memorable shot in recent memory, despite the negative result for me.

 

Knowing the probability against such things makes them all the more interesting to see, and it's one of the reasons I love 40k.

[Chengar Qordath]

61% is the probability that a blast will scatter less than 2 inches from the initial target, whether because you rolled a "hit" on the scatter die, or the total scatter was 6 or less. And I don't have it with me to measure, but I think the small blast is 2" radius?

ok thanks, and the small blast is 3"

3" diameter, not 3" radius. Not trying to be a geometry nazi, but it is a pretty important distinction.

[Brother-Chaplain Gaius]

yes, you're correct.

[pattison]

I think there is no use of math when we come to the scatter dices.

You simply have to believe that it will be a hit. Roll the dices from karma! :down:

I roll more hits than anything else in general. I love plasma weapons! :huh:

[Justicar Valius]

Never trust the dice gods, they are fickle and make you roll 8 out 11 rolls 2s or 1s when rolling for your armour saves! never trust them and always sacrifice your opponents HQ to them.

[Chengar Qordath]

Never trust the dice gods, they are fickle and make you roll 8 out 11 rolls 2s or 1s when rolling for your armour saves! never trust them and always sacrifice your opponents HQ to them.

Yes, the random number god is a dangerous and fickle being. One of my opponents once questioned the existence of the random number god and insisted that appeasing him/her/it was just a silly superstition. The next time he had to roll armor saves for his terminator squad he failed all of them; I've never seen that many 1's at the same time before.

 

Doubt the power of the random number god at your own peril.