Ever since the beta, I've been rabidly following the Starcraft II pro scene. The game has been changing on an almost weekly basis, and not often due to patches. As new strategies are figured out, the strategic landscape of the game alters drastically. Here's a look back at the landscape for a perspective on the present and future of Starcraft II strategy.
Early in the beta, protoss play favored almost entirely four gate and three gate robo. Immortals were huge and Colossi were rare. Void ray rushes were very strong, and Terran would go for lots of early marines as a precaution. Expansions didn't really happen much. I don't recall ever seeing a fast expansion from any race but Zerg. Zerg had very few problems getting a fast hatchery up safely. Terrans basically always opened with a reaper or two against every race. Roaches were the primary (and sometimes only) unit in the Zerg army. Mutalisks were basically unseen. The game felt pretty balanced at the time, although mass roaches were very very strong.
Mid beta, we had the first big tournaments, the HDH and finally the Razor King of the Beta. As I recall, during or right before the HDH roaches were changed to 2 food, and roaches fell drastically out of favor. Mass hydralisks and baneling busts because very popular. Terrans were still opening with reapers and moving into helion or banshee harass in most matchups. TvT was in a lot of flux but tank-viking was not around yet. TvZ was almost always Terran doing a large one-base tank-marine push after lots of initial harassment. Protoss began using colossi, as White-Ra demonstrated their effectiveness in the HDH.
Late beta, in the Razor King of the Beta tournament, strategies were very similar, but Tester introduced us to a strategy IdrA still considers to be unfairly strong: double-pylon walling at the bottom of Zerg's ramp, with a cannon behind it. This opening is still used today, but will be weakened in the next patch (as of this writing). Tester also demonstrated his masterful forcefield use in the King of the Beta tournament, in combination with colossi which were quite popular. TvZ had not changed much, with opening harassment into a timing push off (typically) one base. TvP was considered in Terran's favor, with mass marauders being just too strong for many protoss to deal with. Tanks were also viable against Protoss at the time. ZvP, 2-gate zealot rushes were common, forcing early roaches. Muta-ling was also very popular due to the rarity of protoss air. Only Nony (Liquid'Tyler) was known for his phoenix harassment. Ultralisks, all through the beta, were considered useless and not used.
Early release, introduced to the world during Day's midnight launch party for the game itself, came Zerg's most hated strategy: 5-rax reaper. Terrans discovered that they could continue to make reapers and get a quick nitro pack while expanding, forcing roaches instead of drones and pressuring like crazy, and transitioning into a huge marauders push. Zergs struggled to figure out this opening, and after some time the very best Zergs could hold it off some of the time by rushing to spire, using extra spinecrawlers, or getting very fast speedlings and employing impressive micro. MorroW won the IEM tournament against IdrA with this strategy. But it took a mid-game patch to truly put an end to such a strong Terran opening. In TvP, mech was out of style, with mass marauders versus mass colossi being the norm. Banshees were still popular but helions weren't used as often.
Mid-release, the GSL began. With a patch, nitro pack required a factory to be built, and reapers essentially disappeared overnight. Even so, Terran harassment openings and timing pushes were widely considered overpowered against Zerg. IdrA pioneered the use of mutalisks in ZvT, with muta-ling-baneling showing its strength - provided Zerg could get past the early game. This is about when I first recall seeing forge-fast-expands from Protoss, and other fast expansions from the other races. Macro games became a little more commonplace. ZvP, roach-hydra versus stalker-colossi was the norm. Phoenixes shut down mutalisks, so muta-ling fell out of favor.
Most recently, we had GSL2 and GSL3. Foxer was the name of the game, demonstrating the power of raw marines and micro. No one knew marines could beat banelings with proper spreading and kiting. Thanks to this huge shift back toward marines, which had been seeing some disfavor, Terrans are again able to counter mutalisks by keeping them alive against banelings. Tank-marine or marine-thor are now the dominant Terran strategies, but macro Terrans are still the minority. In the finals of GSL2, Foxer again shook up the game by winning several games with marine-scv rushes, which became commonplace in GSL3 and on the ladder. Zergs are still having difficulty dealing with this attack. In PvZ, phoenix openings are becoming very strong, forcing hydralisks and transitioning into colossi. Zergs once again feel under the gun. In GSL3, oGsMC revolutionized PvT with brilliant forcefield micro, early stalker and zealot rushes, and the return of early void rays in professional play. Many people feel TvP favors the Protoss now. Macro games seem to be very common now, even with Terran players.
As we move into the future, we can look back and see what drove the changes to the game and to strategies. Patches were always a response to a change in gameplay brought about by the players themselves. The perceived balance of the game constantly changes due to these player discoveries, and in the absence of any patch. Already we're seeing more and more long and exciting games in every matchup, and we're bound to see more as strong early attacks are ironed out of the game, thanks to player discoveries like new micro techniques or better building placement (as Jinro showed us against Fox.Moon on Scrap Station). Starcraft 2 has only been out a few months, and I can't wait to see how the game develops next in 2011.