Add heavy cruisers and flak frigates; those are very effective counters.

Turrets don't qualify as a counter anymore than a starbase or minefield does; too easily avoided.

Support cruisers with disruption abilities, such as the Hoshiko, Guardian, Subverter, and even Subjugator perform quite well against them.  As a result, they can qualify as a counter even though they don't "damage" these units directly.

Like strike craft, turrets are not a capital ship counter in the sense that they're too easily avoided.

In practice each capital ship operates differently and preferred counters vary dramatically, so there's no universal rule to countering them.  Really, "countering" them is a matter of choking them with firepower, which means light frigates usually do a better job than other capital ships.

Scouts cannot attack bombers.  Flaks can.

Since the title only says counters to ships and not ships that counter each other, I think structures must be considered fair game in the discussion. With that being the case, I would place hangers with Phasic Trap and Flak Cannons in the SC counter category as well.

LF counters Seige frigates and flak.

The Cap Ship Category depending on particular ship and abilities could be said to counter most everything.

Actually, scouts counter siege frigates.  Faster, cheaper, and about the same damage as a LF when attacking light-armor type units.

No capital ship will counter a large force of damage-dealing frigates.  As I said, the way to kill them is to choke them with firepower.  If you can pelt them with enough damage, the capital ship will fall.  There are some good protection combos you can pull to mitigate this, but these are pretty universal.

nvm

Well done mikey39800. Though I would have made flak frigates a great counter of bombers rather then an excellent counter.

LRF will only beat heavy cruisers if you have support cruisers to disable the heavies, which is really more a matter of the support cruisers countering the heavy cruisers and the LRF are just bringing the firepower to the party.  In a straight shootout with relatively similar fleet size, heavies will win rather handily against LRF. 

I told myself that I wouldn't get bogged down with minutiae over this chart as the Whole Wide InterWeb will never completely agree with me, nor was the chart originally intended for anyone but myself. But dbkita has valid concerns over a detail that I feel is the most debate-able point of the entire chart. In short, I've spent a lot of time considering it.

First off, I completely agree with you dbkita. I was/am on the fence about including the blue arrow. As of now, I think LR frigates do 75% damage vs. heavy cruisers and don't have good survivability. The reasons I am choosing to include the disputed blue arrow are as follows:

A ) This is a personal quick reference chart designed to aid me in the heat of battle i.e. I use this strategy. No one else has to. I feel strongly enough to leave it in, but others are welcome to reproduce the chart and take it off or reject my assessment all together. Quantifiable data is different than defining the quality between words like "good" and "great". This makes my opinions easier to defend, which is why I even submitted this to the internet in the first place. Take any strategies offered from someone with a grain of salt, as they may not be good for you or even all situations.

B ) Heavy Cruisers are inherently difficult to counter based on their stats and I didn't want to chart their "invulnerability" because that helps nobody fend them off. On that token, Long Range Frigates do the same percentage vs. Support CR as they do heavies. I left this data off because of my intentional chart simplicity and also because their damage type isn't that good in the first place vs. cruisers and there are two counters already listed against support (Light Frigs and Heavies).

C ) Support cruiser abilities are useful in countering heavies, but my "disclaimer" negates the consideration of abilities on this chart. I also wanted ships/structures to be generally effective at killing or staving off the countered ship and there is more micro involved in Support Cruisers countering Heavies. For that reason, I chose to give the credit Darvin3 gave to the Support CR to the ones dealing the damage.

D ) The red arrow pointing from Heavy Cruiser to Long Range Frigate should also be an indicator of how effective the reverse counter should be.

E ) My little "disclaimer" on the chart says the rest. Use combinations. Use angles, speed, build time, resource cost, research, and individual race strengths to your advantage. Micro does wonders. Attacking fleet composition is also a huge difference when considering the scenario you mentioned. This counter may not be effective if outsmarted by a better counter or even just a well-balanced fleet.

Happy hunting and I hope the chart helps. I don't believe I'll be making any more adjustments. I hope it helps the Sins community which has made me a better strategist in this amazing piece of gaming. I'd love for it not to have flaws, but anything someone produces that isn't a recitation of cold numbers will be arguably accurate depending on the recipient.