I didn't want to pollute the
genestealer thread with more stats discussion, but in case anyone wants to exercise their brain I'll put this here. I will put forward the argument that considering variance can give you a modest advantage as a general and is worth considering for list design.
Evil and Chaos wrote:
Quote:
But slavishly balancing around the "average" is not looking at the broader picture.
It's a more useful metric than looking at one side of a bell curve under restricted circumstances.
Especially as getting unit stats right is more often an art than a science.
Moving on from genestealers, to address this point in a more general sense as I see it a lot: probability distribution is usually NOT a bell curve. This is only the case for 4+ rolls. That has been the whole point of the genestealer discussion (albeit used to support different and separate assertions), and why looking at the distribution IS a more useful metric than the average.
Take 2x5+ vs 3+. These two rolls have exactly the same average, but the latter has a lower chance of getting 0 hits and a higher chance of getting 1 or more hit. You can ignore that if you like, but it does have a marked effect on how good the unit is at its specific role, and interplays with the formation size to determine how good the formation is as a whole. To whit: if you have a large formation and are going for a strategic win (i.e. the odds are in your favour and you planned on winning) you want 3+. If you are a small formation, are looking to deter an assault, or make a last ditch kamizake attack, you want 2x5+ because in all of those cases you are relying on "getting lucky".
Clearly this has consequences for list designers. Yes statting is an art (if only because we aren't clever enough to conceptualise all the maths), but it can still be guided by the science.
As a more general observation, if your decisions to assault are based on achieving the average, with the greatest respect IMO you are making poor strategic decisions. That is because the chance of getting average hits or better is actually only 50/50. I know that is not how my mind works during a game; I cant'/don't do the required factorials in my head on the spot(!), so I am looking for the average to be "some margin" higher than what I need to compensate for this effect. It is a poor approximation of reality, so it is useful as a general to bear in mind that with lower rolls, this margin actually does not need to be as high.
Anything that adds or removes variance to the result is affected by this. First strike, for instance, raises the variance by magnifying the impact of hit rolls and armour saves. Conversely, macro weapons eliminate the variance introduced by armour saves. It is also why blast markers and inspiring characters are so good - because they have no/minimal variance - it makes your estimations as a general more accurate which gives you a strategic advantage.