So I took it easy today, as opposed to working my ass off at god knows what. I played a bit of starcraft 2 1v1. Just 3 games, I indulged in, nothing more than that. The first one was a loss; I rolled Terran against a 'toss and promptly went 6rax marines which failed miserably against his sentry stalker spam. Then I proceeded to win 2 games in a row, a pvt in which I 1gate expanded into 8gate chargelots into stalker spam (I switched to stalkers once i saw the banshees) and a tvp where where I went 6 rax against a proxy gate rush.
What I find fascinating about this game is how much positioning matters. I could have easily lost both of those games if my army was in the right place at the right time. For example, in the pvt, my opponent had bunkers set up outside his natural, so i just walked straight past them and attacked his main, then I slaughtered his army as they walked up his own ramp back into his main.
But even when it comes to big army battles, positioning matters. a concave formation does a lot more damage than a ball formation, except when flanked. As numbers increase, melee units dies more and more easily to ranged etc etc. And this accurately reflects real life.
Ultimately real battles often come down to who has the bigger army. Good positioning though can nullify numbers/technological advantages though and win the battle outright in the right circumstance.
The most famous example of this is the battle of Thermopylae. If you have seen the so-bad-it's-awesome movie "300", this movie roughly documents that battle. Spartan armies, like Greek armies, work best in formation and the phalanx formation is a directional formation; it is strongest at the front but very vulnerable to flanking. By meeting the army in a mountain pass, the Spartan/Greek army eliminated the possibility of flanks and surrounds and played to the strength of their formation. The Greeks lost of course, but not only because the Persians managed to flank them using an alternate route, (another example of good positioning).
In modern times, battles are fast paced in comparison but positioning is still important if not as crucial as ever. In the American Civil War, Robert Lee won many a battle by simply having a well positioned army to meet and create threats where they came. The battle of Fredericksburg is a good example of where he utilised urban combat and well positioned artillery on high ground to his advantage.
And in World War 2, Germany would have never conquered Europe (save for britain and a few others) if they did not actively bomb enemy railroads to ensure that their enemies' armies were never positioned where they needed them.
So there you go, when it comes to winning battles, it is all about location, location, location.