The pirate fleets that I encounter are no where near that kind of strength. Whenever I fight the pirates they usually are somewhat easy.

I've run into a few fleets, your best bet is to steer clear of them if at all possible. That is, unless you have some bonuses, 2 fully upgraded military mining bases worked for me. Then it's killing time

For the most part, don't tangle with pirates. Unless they're right on top of your planets or on a major trading route, it's best to leave them alone.

If you do have to take them on....

You basically have to custom design a fleet (or two or three) specifically created to take on that pirate fleet. If they have missile weapons and shielding, design ships with heavy point defense and nano rippers (or better).

When they spawn -

They will have weapons, defenses and engines equal to the latest generation that you have researched. Or maybe equal to the most advanced race, but that's usually me, so who knows...

They will have insane logistics that you cannot match. They will have insane miniaturization that you cannot match. You'll just have to have enough firepower to blast through their escorts and kill the heavies.

Either use heavy fighters exclusively or use 1-2 frigates/battleships plus heavy and light fighter escorts. Use your most devastating weapons that aren't countered by their defenses. Or if you have Phasor VII or higher, you can pretty much ignore any shielding they might have, as long as you pack enough emitters onto your ships.

This is what works well for me:

Logistics = 43
Dreadnought x 1
Frigate x 2
Heavy Fighter x 5
Escort Fighter x 6

Make certain your dreadnought/battleship's defense/attack ratio is higher than your frigates, that your frigate's is higher than your heavy fighters and that your heavy fighters' are higher than the small fighers. In other words, the smaller the ship, the less defense it can have compared to firepower. This is so that the enemy shoots at the smallest ships (the escorts) first and hopefully never shoots at your largest ships.

You have to be careful when you put defenses on an escort. If you don't match up all the ships in a fleet just right, the AI becomes confused and comes to the conclusion that you are using a massive hull vessel with 100+ hit points to escort a horde of tiny hull vessels with 10-15 hit points. When you put them all into the fleet, the smallest ships should be listed higher than the larger ships and your really heavy ships should be right at the bottom.

I've seen the popup announcing the pirates a few times, but I've actually only seen them flying around once. I ignored them and let them go about their business, but I noticed that they were powerful, far more powerful than anything I had. Perhaps that is why I left them alone.

I had a pirate fleet showed up with some 400+ attack in all 3 areas. I was like whoa... finally time to pull out my blackhole erruptors (I was just cleaning up the end game at this point). The turn afterwards they dove into my fully fortified military base and all died. Damn it, so close to a challenge.

Pirate fleets in all my games have immidiately been stamped out by the other race factions. This thread kind of makes me laugh because I 'd like to tangle with pirates, but they're always killed off before I get to have my fun with them.

I have once seen 27 pirate ships massed together but luckily not as a fleet (phew). I had the prison planet so I had to beat them down, bit of a pain but luckily I wasn't in a war (fighting proxy wars) !!!

EZ

AR

The only pirate fleet I ever saw was super weak, but it snuck in a blew up one of my economy starbases . Suffice to say I was pissed off and proceed to obliterate them