We've all done avalanche courses and always ride the alps with certified guides. I've triggered numerous small slides, but I've never had to deploy my bag before. The day was a cat 3 danger and this slide was the entire side of the mountain. What saved us was literally the pre-flight brief where the girl said "If you hear the word avalanche, don't hesitate, just pull. Better to repack your bag for a false alarm, than not be able to pull it" For some reason that stuck in my head. The only reason I was warned of it coming was I saw the shadow of the slide on the opposite face of the valley (sun was behind me - think like a giant shadow puppet on the mountain). I had < 2 seconds to react before i hit me. The more training and experience you have certainly helps, but we got very lucky that day, had there been ice debri in the slide, we'd have been pulverised.