Valve have sat down with Area 51's Semphis and a video camera to talk through some pro strategies for improving your odds in Counter-Strike: Global Offensive. Semphis offers detailed advice about how to fire the AK-47 at different ranges, and shows some of his favourite grenade arcs. Advice like "aim above the third strut to get a smoke grenade to the Library" is exactly the sort of precise instruction that'll come in handy the next time you find yourself rushing around that corner on de_inferno.
This is the first in a series of Pro Tip videos that Valve plan to film as they travel around visiting teams. Valve seem to be warming to the idea of producing films. They announced that they're working on a Dota 2 e-sports documentary earlier in the year. It'd be great to see some Dota 2 tips videos from Valve as well, but who knows what they'll do next.