How many planets do you build starports on?

I only build Starports on worlds were I will be building ships. Generally only Class 9 and above. It is working out well so far but I am just now playing on normal. I think it is a waste to use up a planet tile for a starport when the planet only has 5 tiles. It wont be able to crank out my ships fast enough so I would rather use that tile for research or economy. Sometimes a trade good or super project.

all of them unless they are really low class.

I like to have the ability to pump out ships when necessary. plus.. even if it takes a planet 40 weeks to build something... in 40 weeks that is a ship that I wouldnt have had otherwise.

usually.. if a planet is so small that you have to worry about whether or not you can afford to use a tile on a starport... then I doubt you would see any great benefit from putting a factory, research center, farm, embassy, whatever on it.

I usually put them on all planets, even the low PQ ones. I never know when I'll really want to buy a constructor/interceptor NOW, and a low PQ planet is the only place close to where I need.

I build starbases on every single planet. I dont like my military production going to waste on any planet lol. If you dont like it there you can always upgrade it to a different building later. a 3PQ planet (2 factories 1 starport) can pumpout tiny/small fighters fairly quickly.

quality 6+ will get a starbase. quality 5 and lower will be pure research or trade centers.

Depends on how many I have existing already. If I have a string of planets that are pumping out medium-class ships in under 10 weeks, i usually don't bother putting starports on low PQ planets. On the flip side, if it's early in the game, I put a Starport on low PQ planets until I don't need them anymore. Then I demolish 'em and throw up research or something.

I try to have an economy starbase covering any planets I plan on doing ship production on, and a military base on as close to every planet as possible.

Protip: Upgrade starbase weapons and armor before you install other modules. You never know when you'll find yourself at war with someone.

I build starbases on anything 6+, mainly because even the worlds I don't plan on building any warships with will still be pumping out constructors. Constructors are my default ship that all planets build unless they have a reason to do something else from the beginning of the game to the end.

Only on those above 8 class, and that of course depends of how many planets with starports i have, because running a expanded military industry you might get bankrupt.(you lose a lot of money to run them at full capacity).
So ib concluzion, depends of how many planets i have, how many Ai players and my positon on the map

I build on all planets. Because again, I don't want to waste the military production. And what else are you going to build...factories? To manufacture what?

I build starports on all planets too. Ships are the "currency" of expansion, development (constructors), and war and I can never have enough of them. I generally only build constructors on smaller worlds and they take forever but every extra constructor helps - and you can always switch out, switch out and do a buyout and a mostly build ship, and/or build smaller warships too.

On larger maps and/or once you have a large number of highly productiveworlds, I could see getting rid of starports on the smaller planets in favor of more research or econ buildings. But, on medium, small, or sparse maps you won't have a huge number of planets and every extra ship (and ship producing planet) helps.

Seems I'm being rather reserved compared to other people on my starport deployment. I only tend to throw Starports on Quality 10+ planets, unless the lower quality planet has a manufacturing bonus. Then I tend to make it into a pure production planet. I generally make my smaller planets either economic or research centres.

Protip: Upgrade starbase weapons and armor before you install other modules. You never know when you'll find yourself at war with someone.

Generally agreed. The first Starbase Fortifications tech is cheap, and turns starbases into something virtually untouchable at that stage in the game. Sometimes, if it's REALLY early in the game I might prioritize mining before weapons/defenses, but only if that region of space hasn't come in contact with any other races yet.

I generally make my smaller planets either economic or research centres.

Better off going with research, since it doesn't depend on population, but economic does. A class 4 planet is going to cap out with a population of what, 2.5B? That's only half the population that the colony will provide food for, so your tax income there will stink, even if you put econ improvements on all three remaining tiles.

And am I the only one who hates getting food bonus tiles on low PQ planets? That's an insult!

...In a related question, does anybody know why the AI will put an Economic Capital on a PQ4 planet?