Monday, 30 June 2014

List building and unit comparison

Last post I talked about my list selection and the theme of my army, some of my choices were difficult to make. Multiple  desirable units occupied the same force organisation slots. I used theme to thin down my selections but how do I choose between special weapon PDF squads form Damarus, narco tribe mercenary Ogryns from Footfall, and land ship storm troopers  from Zarth.
All of these units fit with my theme, could be embarked in a Valkyrie and dropped off behind enemy lines to strike a sensitive target. How do I make my choice? I need to somehow compare the points cost and abilities of each squad against the others. Enter; Mathematics, working out the likelihood of wounds caused by shooting compared to the points would give me the shooting efficiency of each squad. So it was pretty easy to work out the potential wounds caused by shooting. The formula I used was. Chance to hit x Chance to wound x Chance to fail save x Number of shots = Kills
So comparing some of my guard units shooting would look something like this.

Assuming that the target is a Space Marine

Infantry squad:- ten lasgun shots
.5 x .3333 x .3333 x 10 = .5554 (therefore on average ten lasguns equals half a dead marine)

Ogryns:- thirty. ripergun shots
.5 x .6667 x .3333 x 30 = 3.3331 (therefore on average 10 riperguns x 3 shots equals 3 & a bit dead marines)

So on the face of this it looks like the Ogryns are the better choice over the Infantry Squad.
But this simple formula doesn't take points cost into account.
So I was just going to divide the Kills by points cost of the unit. But at the same time, my Google-Fu turned up Simhammer. This site is a treasure trove of info that works to simplify the "Mathhammer" of 40K. The Dakka Per Point (DPP) algorithm does exactly what I was trying to do and it gives a comparable value to the Resilience Per Point (RPP) algorithm. With these two values Simhammer goes a long way to creating a method of working out the efficiency of the units perhaps the last corner of the true-value triangle is movement, I am not sure how to work that one out. Simhammer also provide the algorithms in Excel format.

So if I run the same two units through the Simhammer algorithm this is what I get.

(To hit x to wound x failed save x failed feel no pain x number of shots) ÷ points cost x 1000

DPP Infantry squad
(.5 x .3333 x .3333 x 1 x 10) ÷ 50 x 1000 = 11.108

DPP Ogryns
(.5 x .6667 x .3333 x 1 x 30)÷ 410 x 1000 = 8.130

So when shooting at marines, an infantry squad is more efficient then a squad of Ogryns. Even with the higher strength riper guns that produce three times the number shots of a infantry squad. The chunky Ogryns are just too expensive points wise.

Armed with these tools I was able to determine what units were the most efficient use of points in each force org slot.

Perhaps now with 7th edition out with its unbound army list rules, I could use the DPP and RPP algorithms to identify the most efficient unit in 40K and take a full army of just that unit.

I didn't even get to play one game of 6th Ed.