Chapter Three: Calculating Basic Cost Effectiveness

The comparison of Dark Eldar and Space Marines starts at the fundamental level; their basic statistics and armament.

Dark Eldar Warrior vs. Space Marine: Preliminary Calculations:

First, the cost-effectiveness of the basic models are compared, based upon statistics and armament.

Basic Model Statistics
	Points/Model	WS	BS	S	T	W	I	A	Ld	Sv
Dark Eldar Warrior	8	4	4	3	3	1	5	1	8	5+
Space Marine	15	4	4	4	4	1	4	1	8	3+

Based upon these statistics, the cost-effectiveness of one model against another in the assault phase is calculated.

A Dark Eldar Warrior close combat attack will successfully inflict a wound on a Space Marine 1/18 of the time ((1/2) * (1/3) * (1/3)). A Space Marine close combat attack will successfully inflict a wound on a Dark Eldar Warrior 2/9 of the time ((1/2) * (2/3) * 2/3)).

So, for each point spent on Dark Eldar Warriors, 5/48 (0.104) points of Space Marines will be destroyed. ((1/18) * (1/8) * 15). For each point spent on Space Marines, 16/135 (0.119) points of Dark Eldar Warriors will be destroyed. ((2/9) * (1/15) * 8).

However, initiative has not yet been factored in. Since a Dark Eldar Warrior has a higher initiative, a certain number of Space Marines will be removed before they can attack. One point of Dark Eldar Warriors will destroy 5/48 points of Space Marines. Thus, factoring in initiative, one point of Space Marines will only destroy 43/405 (0.106) points of Dark Eldar Warriors. ((43/48) * (16/135))

One point's worth of Dark Eldar Warriors can expect to inflict 2025/19440 points of Space Marine casualties, while one point's worth of Space Marines can expect to inflict 2064/19440 points of Dark Eldar Warrior casualties. So, a Dark Eldar Warrior will be 98.11% (2025/2064) as efficient as a Space Marine in close combat. A Space Marine will be 101.93% (2064/2025) as efficient as a Dark Eldar Warrior in close combat.

This simple statistic, though, is changed in different close combat situations. The following tables present the results of various calculations made to reflect various possible close combat situations.

Close Combat: Dark Eldar Warriors vs. Space Marines
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/48 (0.104)
Space Marine	43/405 (0.106)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 2025/2064
2025/2064 = 98.11%; 2025/2064 = 101.93%

Dark Eldar Charging
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/24 (0.208)
Space Marine	38/405 (0.094)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 2025/912
2025/912 = 220.39%; 912/2025 = 45.04%

Dark Eldar Charging Into Cover
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/24 (0.208)
Space Marine	16/135 (0.119)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 225/128
225/128 = 175.78%; 128/225 = 56.89%

Space Marine Charging / Space Marine Charging Into Cover
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/48 (0.104)
Space Marine	86/405 (0.212)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 675/1376
675/1376 = 49.06%; 1376/675 = 203.85%

With the preliminary calculations for close combat completed, the next step is to calculate the relative cost-efficiency of basic Dark Eldar Warriors and basic Space Marines in the shooting phase.

Dark Eldar vs. Space Marines: Single Shot
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/36 (0.139)
Space Marine	32/135 (0.236)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 2025/912
75/128 = 58.59%; 128/75 = 170.67%

Dark Eldar vs. Space Marines: Two Shots
	Enemy Points Destroyed per Points Spent
Dark Eldar Warrior	5/18 (0.278)
Space Marine	64/135 (0.474)
Dark Eldar/Space Marine Point Cost Efficiency Ratio: 2025/912
75/128 = 58.59%; 128/75 = 170.67%

The cost efficiency ratios for the individual models are now known. These ratios, however, do not reflect the actual efficiency of Dark Eldar Warrior Squads and Space Marine Tactical Squads in combat situations. Additional factors must be taken into account before an accurate estimation of the relative unit cost efficiency of the respective units can be made.

I've put up a Javascript cost efficiency calculator. Note that because the program has not been extensively debugged, it may not work on all systems. Link up to the calculator here: The Mysterious Experiment Page (full of bugs)