Ineffective Anti-Air

[tcart]

I'll take advice/explanations from any who care to comment.

In two consecutive games I'm getting pummeled by strategic bombing. In both cases my AA has been remarkably ineffective. When I look at the combat results my AA is rolling high enough to hit yet no hits are registered.

I've read through the manual but can find no explanation.

I'm curious to know what the 'bombardment evasion roll' refers to as well. Is this part of the explanation? Again, a survey of the rules offers no help.
Regards,
Tim

[Uncle_Joe]

AA is a 'bombardment attack'. Bombardment attacks dont tend to actually kill units so much as put suppression on them. In the case of AA, that means that they can interfere with the bombing runs.
 
In a nutshell, bombardment attacks roll their dice and divide the total by a number from 1 to the EV of the target. This is the amount of Suppression added to the target. When the suppressed unit attacks a number from 1 to the number of Suppression it has will be subtracted from its attack. If the amount of Suppression a unit receives is equal to (I believe) 5x its EV, then it takes a 'hit' and is damaged.
 
So, for a unit with an EV of 5, a when it is attacked by AA its 'Bombardment EV roll' will be between 1 and 5. If it rolls a 5 and the attacking AA totals say, 21 on its attack, then the Suppression would be a very minimal 4 points (21/5). On the other hand, if the EV roll is a 1, then the suppression would be 21(!)...not quite enough to hit it, but probably enough to make its attack miss.
 
The upshot is that, unlike in WaW, in AWD AA units dont tend to 'kill' attacking aircraft all that often. They work better in conjunction with Fighter units, but early in the war they can provide fair defense on their own (before the bombers are tech'ed up to the point where their EV and LA are high). Note that having more AA in a region than there are attacking bombers gives you a favorable modifier on your shots (+2  for each extra, I believe). But its still probably more efficient to add Fighters at that point rather than massing Flak. Flak is a supplement for Fighters, not a replacement.

[tcart]

For some reason I missed the fact that AA fire inflicts suppression rather than direct damage. I'll have to rethink my AA defensive strategy, clearly.

[MrQuiet]

Good answers Uncle Joe but I would like to clarify 2 things.

On the other hand, if the EV roll is a 1, then the suppression would be 21(!)...not quite enough to hit it, but probably enough to make its attack miss.

21 supression points is enough to take down any air unit.
Actually 15 suppresion points (5 x dur3) is enough to take down any air unit.

Note that having more AA in a region than there are attacking bombers gives you a favorable modifier on your shots (+2 for each extra, I believe).

That would be more flack units than attacking air units, not just bombers, although bombers are targeted first by flack.
The bonus for the +2 is that it is doubled for bombardment attack making it a +4 which is like rolling an extra die.

Fighters and flack together are a strong deterant to strategic bombing, much more so if you have the greater number of fighters.

-MrQuiet

[Uncle_Joe]

21 supression points is enough to take down any air unit.
Actually 15 suppresion points (5 x dur3) is enough to take down any air unit.

Yep, its DURx5 as the threshold, not EVx5 as I had originally posted. Good catch.