One of the basic measurements of the offensive potential of an X-wing list is the raw attack dice output. If you're on this forum, chances are you're used to seeing lists evaluated by simply counting up the total number of attack dice. For example, a TIE swarm with eight TIE fighters puts out sixteen attack dice. And sixteen is better than the twelve attack dice a typical four-ship rebel list puts out... or is it?
Counting the attack dice a list puts out is only part of that list's attack value. It's a bad habit, that I suspect comes from the other games with different mechanics, such as Warhammer 40k. There is another, easily quantifiable value that matters a great deal when measuring the offensive strength of a list: number of attacks, (usually also the number of ships).
Here's a dramatic comparison to illustrate my point:
Let's say we have a group of ten HWK-290s with no upgrades. That's ten attack dice, one per HWK. Line them up against a cloaked TIE Phantom at range 2. How much damage do you think these HWKs are going to do? Not much is my guess.
Now put that same Phantom in the firing arcs of two other Phantoms at range 1. They're going to roll 5 dice each for a total of 10, just like the HWKs... but I'm liking their chances a lot better.
They're both rolling the same number of attack dice, but the Phantoms are going to do much better, because the target only throws two sets of defense dice against them. In the Phantom-vs-Phantom scenario, it's 10 attack dice vs 8 defense dice. In the HWK vs Phantom scenario, it's 10 attack vs 40 defense.
The differences are not as dramatic once you start comparing lists that people actually fly, but there is an important difference here. The 12 attack dice from a typical rebel build would go up against 4 sets of defense dice. The 16 from that 8-TIE swarm go up against 8 sets of defense dice. Against a 3-evade target, the difference is 12 attack vs 12 defense / 16 attack vs 24 defense. Attack dice are better than defense, but the difference made by concentrating your attack dice in fewer attacks should not be overlooked.
I always take the number of attacks my dice are spread over into account when making my lists. My shorthand is: #attack dice/#attacks. So a 4-ship rebel list would probably be: 12/4.
What do you guys think? Is this way of looking at attack dice justified?