Quick follow-up. Remember that fighters destroys bombers, which destroy frigates, which destroy fighters.
Here is the incoming massive wave. They also sent a small vanguard of (fast-moving, cloaked) raptors first, but we quickly dispatched those before the main fleet arrived.
Enemy contact! Maginot line is doing its job, tractor beams holding whatever they can while the lightning turrets deal out mass damage throughout the entire area.
It's kind of hard to see what's going on in the screenshot (or in the game when there are 10,000+ units involved in a battle -_- ). The main threat here is the 1500+ bombers, which can potentially wreck havoc through our force fields and destroy the command stations. We need to prioritize those. We're pulling our frigates out of the forcefields via both flanks to try to lure the bombers on them (they'll get decimated if so, but a small price to pay to maintain the base). On the upper right you can also see us mobilizing our bombers out to attack their lagging frigate fleet (bottom of the map, can't see on screenshot). Meanwhile, as their bombers are mostly at the center of their fleet, we're sending our fighters directly on them to destroy them as soon as possible.
While they're not really taking the bait re: bombers --> frigates, they are sending their fighters after our bombers (which you can see on the upper right). We're having our bombers break off to the south-east while trying to hold the fighters off with my (green) screen of frigates conveniently positioned there. Note that I have 107 frigates.
This screen is to showcase that our forcefields have been getting pummelled continuously by the bombers. We've been keeping tabs on which get damaged, quickly pull them out via the nearby warp (where they get automatically repaired by a Mobile Repair Station already set up there), then return them when they get back up to strength.
A more global view of the battle. Our bombers have broken off and are going straight for the frigate fleet at the bombers (with chasing fighters), while my frigates on the right try to stall the enemy fighters as much as possible. Worthy of note here is how uniformly damaged all the enemy ships at the top are. That's from the lightning turrets, which deal damage to the entire area. I don't usually find them very useful since they're not that powerful, but when we have 50 of them and the enemy has grouped thousands upon thousands of units, that's a lot of damage being spread out.
As the battle rages on, attrition takes its toll. The entire enemy frontline crumbles as the lightning turrets kill them off all at once. I will never underestimate lightning turrets ever again. Our bomber offensive is turning to be a big mistake, however, as their frigates are being escorted by 300+ lightning shuttles. Again, it's the concentrated damage that's so destructive here. We're retreating our bombers to the left (all extremely damaged). As I've been pulling my frigates down to follow the enemy fighters, they've also gotten within range of the lightning shuttles. As I was focusing on the top of the battle, I hadn't realized it until it was too late. I now have a total of 3 frigates left. Out of 107. Our bomber strike wasn't very fruitful, either. Not sure how many we destroyed, as the screenshot actually show their numbers increasing via reinforcements.
But that's just a setback. The battle is over, we take care of the shuttles quickly, then loose our bombers onto the remaining retreating enemy frigates. It's a slaughter.
The battle's over. But the AI is already massing up large reinforcements at the nearby planet. The status quo isn't going to work. We need to expand and destroy their raid engines.