Most professional loggers that I've known fell trees by first making the notch in the face, then doing a plunge cut in the back, leaving enough standing on the outside to hold the tree, and cutting to within an inch or so of the notch, then they step back and reevaluate everything, only once they are good and ready do they step up and do a quick whack of whats left standing in the back, and hustle away from the tree (if the tree doesn't need wedges). If the tree needs wedges this method helps that process as well, keeping the saw blade from getting pinched. The wedges are hammered in just before the coup-de-grace. I was told this method is required by their insurance policy, and also helps to not to pull slivers out of high value butt logs.