^ what he said. I should clarify that my comments re scouting for a timing window were not necessarily related to that specific game. Very interesting to watch, I thought the superfast expo was very risky when I first saw it.
Yeah I thought that too. My guess goes something like this: when you reach the pro level, you learn to trust your "game sense" to tell you when it's OK to take risks... and when an apparently risky maneuver isn't risky at all. Like in that game, I think the scariest part was going gas first. After Gretorp's early push, neither side had beans, and I suppose expansion was "safe" in the sense that while you have no defense, the enemy has no offense, haha. Granted I'd be too scared to try shit like that...
Also, similar to the chess world, I'd bet the best SC2 players watch the competition's games--get a feel for what kind of openings/styles to expect & prepare accordingly. I've definitely seen games where one player prepared some kind of opening novelty (e.g., birth of cauthonluck cheese).