I'm a mid-platinum Protoss player, I recently played a few games vs Zerg... some won.. but some... well, Zerg just overwhelms...
For instance: http://ggtracker.com/matches/5153632
Yet at the 9th minute mark, we had similar amount of supply (56 for me vs 64 for my Zerg opponent), but at the 12th minute mark I had 92 supply, while the Zerg had 133... I had some gaps in the probe production,... maybe a 10-15 second gap a few times... Could this make such a huge difference?
What am I missing in my game, since I came that much behind in supply?
P.S. Maybe my game, in general, was ok. Maybe I just needed to have more sentries for the battle around the 15th minute mark and split the opponents roaches/hydras in half? Looks reasonable, but the Zerg still had way too big an army.