Actually, I don't think it has been tested much. There were some tests on the gas issue, but on minerals there wasn't much yet, so it is really not an exact science. If someone wants to do some ressearch on it, do it ;)
I tried, but it is completelly impossible. You get totally random results every time even though you are using the same mineral patches.. One could think that diferent patches (1,2 or 3) had different properties (which they do) but i didnt really expect that patches of the same type also would have different properties from time to time.
Example. If i put a (1) mineral patch on a certain place around the CC the scv will go straight to it and gather, then return. But occasionally it will take another completelly different route just by random and there is no explanation to that. The results i got from similar mineral lineups were sometimes totally different and that is why i gave up the idea of trying to test it.
The Sattarchasm layout (which is throughout my later maps, not just sattar) is just a average placement to try to make up for the biggest differences in placement. I thought tha since workers are spawned below your CC and not above, it must be quite imbalanced if one player starts with minerals above, and one below (like 12 v 6 on LT). Therefore this placement is better since you got almost the same distance nomatter what side of base you got your minerals on. I wonder if bill even gave this a single thought before he made satterchasm+ ... modified by Starparty
Yeah, there isn't really an effective way to test mineral placement. If you think about it, one player will never use the same amount of peons as his opponent, even in mirror match-ups. So mineral balance doesn't have to be precise. However, it is important to keep each players' minerals visually equivalent (similiar placement on both sides, not necessarily exact). modified by Arden(WoF)
it shouldnt matter as long as they are equal for all players. past the first 2 minutes it makes no difference anyways unless one base has some patches like 3 or more squares away from the closest spot to the CC and other bases dont.