I haven't yet posted this article, but thanks to jomini's excellent analysis above, I've updated the KC/Goons/Masq article. Which, let's face it, was seriously out of date. Let me know if there's anything else that should be added.
A few things I would note:
1. Multi-player pins are possible, just hard to pull off. A simple example is Kc/Scheme/Militia/Outpost/Kc/Masq:
Kc -> Sc -> Mi -> Op -> Kc -> Mq
Kc -> Sc -> Mi -> Kc -> Mq
That will pin two players in 3er. Obviously these are even more rare and even slower than basic pins, but they are possible. 4er pins are likewise possible, but they involve shenanigans with NV, golem, and KC so I think a simple line that most pins don't work in multiplayer is fine. As more cards get added to dominion, so far, it looks like the pin is getting easier and the multi-player pin is getting easier even faster.
2. I maintain that VP chips are mostly irrelevant to the win. Goons is likely the worst card to try to use for a pin. It's expensive so you have to build up to it, it lacks draw so you need a cantrip to avoid having to pass a key component in a discard -> masq situation, and it provides points to the opponent who may be able to pile out the curses for a win before you can overcome their accumulated goons points, and lastly masq/goons heavily encourages the opponent to use the masq for draw/copper trashing and just muck up your combo to no end. I think the best combo is either Kc/Masq/Outpost - very little innate engine potential, 5 cost enabler, and immune to reactions or TR/TR/Minion/Outpost/Masq - cheap and quick. Stuff like militia being cheaper or ghost ship and margrave having + draw should not be over looked. Once you get the opponent down to no cards you can now buy copper (if you need it) and build up while having 5 extremely strong cards in your starting deck, the opponent has nothing; if you can't win from there (barring something flukey like 4 provinces on the NV mat), you really need to work on the basics.
3. I would stress more the utility of cantrips in the pin. Cantrips mean that you are much less vulnerable to being hit with a game winning masq on your one turn of vulnerability. They also let you go Kc -> Cantrip to draw the rest of the pin and play it -> discard -> Kc -> Mq if you've been hit with a discard attack. Having a cantrip out makes the pin a much safer play against a knowledgeable opponent.
4. Part of the counter-combo is that you also go discard -> masq which is just brutal to an ultra-thin deck. Against a single masq, hey you have a left over chapel or some other terminal you can pass over, or as noted a cantrip. With discard -> masq you can only make the pin next turn if you have Kc/cantrip/dross in hand. If you want to fight the pin rather than race it, build an engine that can play discard & masq every turn. It really hoses the pin player.
5. Masq also helps by giving the opponent a card they have to trash before you are fully pinned. You only lose two cards the next turn and one card may be enough for you to survive or setup something killer. E.g. You play masq and send over a copper. They semi-pin - passing you a copper which you pass back and lose two other cards. You play menage, kick off your engine, and pass another copper, and gain 3 or more cards. When facing a pin you almost always want to send over treasure or VP instead of actions, if you really must send an action, a terminal is far better to send than a cantrip.
6. Governor and Embassy both work quite well for disrupting masq pins when you are trying to delay the pin until you can win. Feeding your opponent silvers that they have to pass to you slows down the pin immensely. KC/gov can ensure that you aren't pinned this turn and hopefully set up a turn of KC/gov/gov for next turn. Likewise, Noble Brigand can be absolutely show stopping for a pin, if they don't have 6 or more cards, you can only give them a copper a turn, however if they did take the strong route and overbuild their pin with many cantrips, you can give them scads of coppers. If you do give them just one copper, this means you will have a one card hand next turn which may be fine at letting you set up another disruptive NB play (e.g. KC/menage/NB is quite good). Also during the build up, stealing silver is evil to guy who needs two KCs, copper dumping slows down the pin, and of course, you can use your gains to build up a nice counter deck. Ambassador is the final card in this set, you can completely nerf a pin by going Kc -> Am (reveal, but don't return a copper).
