To add to Scotty's post, when he is talking about the undercut, he is referring to when the trunk is off the ground. As you start cutting at the very top, the tree is touching the ground so there is pressure so you will do most of your cutting as undercut. As you do this, the tree will continue to fall. How far this will happen depends upon how well it is still fastened at the break.
Only takes one pinch to learn to cut from the bottom. A bit more tiring, but valuable technique.
Going back to the picture I posted....I'm sure it's soft maple.... thinking boxelder. Thoughts from the members here?