To block or not to block?

[JohnUcrazy]

I only wall-in against Zerg because of a fast Zergling attacks and Zergling runbys, against other races I usually build close to my mineral line.
Supply Depots can not only be used to block ramps, but also to create small gaps inside your base or even completly close gaps; then your opponent has to run around your entire base to attack your army/workers.

Agreed. Walling against Zerg is more effective than the other races. Walling with just supply depots can lead to trouble however. Against T/P, building in a compact style helps protect buildings and minerals lines in the early game. This way your "sim city" works to your advantage, in which will help you progress towards the mid/late game.

Walling against T/P can work, but not as effective as they have units that can easily out range you to take down the wall sooner than you think.

[//MavericK\\]

Ok I forgot to add something, 6 pools.

On 1v1 maps (I've tried this) the timing for you to make a wall to block off a 6pool is cutting it REALLY close. IF you want to make your barracks in time, you need to travel and then construct it ASAP (usually means your SCV is idle'ing).
It only takes a 5-10 second margin of time gap to let a 6pool destroy you.

I always assign three workers to the wall-in with zerg. I rarely have a problem...even with a 6pool. Lost money gets recouped from a mule drop or two and I send one of the three scvs out to scout rather than burn energy on a Scan. The other scvs either go back to the mineral line or become my primary builder scvs. What ever the situation calls for.

I'm thinking about getting away from the wall-in strategy against Toss and Terran. It's just not as effective or necessary. I'm liking the strat with one bunker at the ramp and the rest of the base near the mineral line.

[Sigel]

If you're against a 6 pool there's no need to wall in...you just have to wait for the zerglings to run to your workers and attack move with all of them...with good micro you won't loose a single worker and with no macro you'll still be left with a HUGE worker advantage.
6 pool is an all in rush that only works against new players who panic when they get attacked or are loosing a lot of time very early in the game by not knowing what to do. If your build is smooth during the first 4 minutes and you don't panic then you should win against any 6 pool.

The only time when a 6 pool should potential be fatal is on 2v2, 3v3 or 4v4 when multiple people are doing it as the number of lings becomes potent.

Still walling in is a good start against zergs as it prevents run by from a 10 pool or so.

It also tends to have use against early zealot pressure from protoss but it can be less important in that case.

[dejai]

It is completely situational. Lots of professional players do not wall in. If you have exceptional marine micro and you have scouted marines can kite zealots forever (without charge) and you can deal with that harass. However I don't know why you wouldn't just wall in because A: Saves you having to deal with marine micro. B: Prevents instant lose to 6 pool. C: Prevents most likely instant loose from 2 Gate pressure. D: Stops early scouts. In other words what would you gain from not doing it?

[Dalarsco]

I always block, even on TvT on the off chance they open with someone other than reapers.

[ChAoS]

You should always block every game no matter what. Never with pure depos tho. You only block your techlab if you don't wall properly and you shouldn't wall with more then 1 depo if your vs zerg. There is no downside to walling. Some strategys like air rushing and making reapers or doing a 6 pool will get around the wall, but so what? It's there to help, but making the wall doesn't force you to 100% rely on it. It's a just in case feature.