Also, I was helping the new guy get a sense for how missile defence worked. I'll actually copy that PM here, because it's a compilation of info from earlier in the thread:
You're right that [the rate of learning about the effectiveness of missile defence is] unrealistically slow, but the truth of the matter is that I don't have hard and fast rules myself. Here's what I do have:
My rule of thumb is that 2 AC/2 is as good at point defence as one MG. When AMS exist, they'll be twice as good as a MG. Other weapons are mostly irrelevant.
We also have battle reports with relatively solid numbers:
1) Turn 2, 2 Galahad and 4 Albion(252 MG) resisted an attack of 80 missiles with only minor damage.
2) Turn 2, one Qinru Zhe(120x AC/2) was crippled, but not destroyed, by a missile strike from 108 fighters.
3) Turn 3, 200 missile tubes plus 300 fighters attacked 1 Galahad and 2 Albion(126 MG), causing heavy damage to the two Albions.
4) Turn 3, 153 fighters attacked one Phalanx(88 MG), and "excellent" defensive work shot down 3/4 of the missiles. (Though the Phalanx did still die to a lucky hit)
5) Turn 4, "over 1000" missiles attacked a Terran fleet(640 AC/2). Roughly 200 were shot down, roughly 500 killed four battlecruisers, and "over 300" were wasted on overkill.
It's important to remember that performance will vary based on rolls. A skilled crew will shoot down more missiles than an unskilled crew, and a poor commander will leave their ships unable to properly support each other. No single one of those results should be taken as typical. Also, the defensive weapon counts include all facings on a ship - in practice, only about 1/3 of those guns will be able to bear on any given attack. Conversely, they don't include defensive fire from supporting craft.
Still, from that we can reach some tentative conclusions. In a really good situation, each mounted MG can knock more than one missile, even with very few targets. In a really bad situation, it takes about 3 mounted AC/2s to knock down a single missile, even with abundant targets. An average of ~125 missiles hitting their target will kill a Black Lion with 480 armour. And the numbers in battles #3 and 5 are really hard to reconcile - I think I went easy on the FedSuns overall, because they either lost less than they should have in #3 or killed more missiles than is really plausible - maybe their support craft were fitted for anti-missile work? I know the Taurians also rolled really poorly in that fight.