As it has been firmly established many times before, SC2 is fundamentally different from SC1 in terms of mining and mining efficiency. The pathing and behavior of workers is significantly improved.
Well, for some time I had been grappling with WHERE to put static defenses near mineral lines. Should I put them behind the minerals? Near the gas? But I had assumed that putting them INSIDE the mineral line, where the workers would have to walk around them, would be a bad idea. Afterall, workers would just have to make longer trips back and forth between the minerals, and theoretically that should cut my mineral intake.
But I decided to run a quick test, and I found that the impact of buildings inside your mineral line can be nearly insignificant. In fact, with 3 properly placed buildings, the impact seemed to be less than a single worker.
Now, the income tab in SC2 is prone to a lot of random noise, which can make exact estimates difficult. But by carefully viewing the range of numbers during each individual case, we can see that the impact of the pylons seems to be less than a single worker. 19 mineral workers with pylons actually yield a slightly better economy than 18 mineral workers with no pylons. The two pylons used that slightly impede probe movement near the gas seem to have no effect whatsoever, since probes already have a small waiting time buffer when a geyser is saturated.
With this in mind, is it worth it to build your static defenses inside your mineral lines when you're expecting harassment?
cannons and turrets fucked shit up in BW but everyone did it because its more important to keep units out of your worker line than messing up mining paths
so if the effect is insignificant then obviously its advantageous to put spines/cannons/turrets in your mineral line.
I know I'm going to... =D I was concerned about restricting the movement of workers myself, but it seems there isn't much to worry about. It means I can place turrets, etc. within a shorter radius around my workers making it more difficult for them to be focused down.
I think most people 'kinda' knew of this, but it's actually quite important. I'd say it means that it is much more effective to build defensive structures in the mineral line if you want to protect workers.
I quite often throw a spore crawler into the mineral line, it's a prime attack spot for mutas and banshees, I guess it depends on how close I am to the edge of the map, how big I perceive the threat of air cheese on my mineral line and if I think I can get away with throwing down static defences behind the mineral line or at the sides instead.