One of the online dictionary definitions for critical mass are as follows:
"an amount necessary or sufficient to have a significant effect or to achieve a result."

I've been thinking quite a bit about army lists. Much of it probably has to do with the amount of tournaments I have been to recently, the upcoming Michigan GT, and the not so distant one at U-Con.
I've been pondering today about"critical mass" in a list. The other day I was playing against one of SeerK's experimental builds. After the game, one of my criticisms of the list was that I felt like it was unable to attain "critical mass". Now, unfortunately, I haven't distilled exactly what I think gives this critical mass, what it actually is, or even if that is the best term to describe it. I can, however, notice when it isn't there. It's absence tends be most glaring when facing an opponent that has a list that just seems to be a bunch of units running around doing something rather than a cohesive force. There is some interplay I can't quite put my finger on between units doing useful damage, units taking/holding important ground, and a general momentum towards mission victory.

Part of the impetus for writing this post is to kind of think "out loud" and maybe get some feedback from you.
Perhaps the phenomenon that eludes me is based off of the general ability to reliably swing the battle in a positive manner. The force required to do this may be what I am meaning by critical mass, but also the ability to keep it from swinging back easily. Anyone can have a really good turn, but a good player with a good list will nearly always be doing well overall through both good turns and bad ones.

So let's look at the generalities that a good list can do reliably.

1. It can deal sufficient catastrophic damage to the things that can deal catastrophic damage to it.

**For example, a tank list that is adept at removing the enemies anti-tank assets.

2. It can run a quality damage surplus. In that it deals more quality damage than it receives.

* I would define quality damage as either succeeding against a target with the right weapons (Lascannons that actually kill a tank, Flamers on weak support troops in cover, etc.) or significant damage to very important units of the enemies (generally just making something roll a lot of saves and forcing wounds. While it lacks in efficiency, if every wound is particularly valuable, it's worth it).

3. Has enough resiliency built into the most important elements of the list as not to be crippled easily.

I think that a list that can reliably accomplish these three things should be able to attain a "critical mass".

What do you think? Am I close but missing it? Do you have a better term? General thoughts?