Chokepoints are areas you know there will be fighting occuring sooner or later. Thats why players turn in strongholds, or at least put some repair bays on it.
A chokepoint can be permanent (ie entanglement to another portion of a system, or planets with direct phase lane to the sun) or for a short time (ie frontline planets, once you take the planet you may scuttle the uneeded defenses and build them on next world).
There can be pirates chokepoints too, usually the nearest planet near pirates base. But they target the nearest juicy planet so it may be wise to add a couple more trade centers on those planets to make it more attractive for pirates. Build tons of hangars, bunch of repair bays and a few well situed turrets and pirates will break their teeth on those. Add a freshly build cap ship in the battle, and you'll get free xp, since pirates are pretty dumb and tend to target trade ships first.
To make a strong chokepoint, added to any "static" defences, you better build at least 2 frigs factories and at least 1 culture center, in order to quick building reinforcements in, and to get the racial cultural bonus. A phase inhibitor may be nice too, especially against ai who will flee if the odds turns in their defavor.
Needless to say that a small fleet of LRM is very welcome when things are quiet (5-10, depending how stade of the game you are), so if a surprise attack occurs, you wont get caught your pant down
, and a few (2-4) support cruisers (hoshiro, guardians (with repulse if possible), overseers/subverteers, mainly) too.
A chokepoint main purpose is to stall an ennemy attack, but human players may try to skip this planet so thats why phase inhibitors come in, and are rarely seen in MP gaming (at least like strongholds with tons of static defenses).
Dont forget to create rally points for any frig factories from nearby planets to the chokepoint, if needed.
