Thats a 440 Mag, they are my favorite. I always buy two together, the sister to this one bit the dust a month ago. Its in the shop now, waiting on a big bore motor kit to arrive. You will understand what I did with that big boy. I didn't want it down in the creek, so I held the hinge wood on the right side, and she rolled 180 degrees on the fall, right in line with the saw sight. Sometimes they go perfect, other times.....well you know !
You leave the hinge thicker on the side you want the roll to begin on. The tree will hang on that thicker side just as the thinner side lifts. If all goes well, you get the roll you desire. Technique does not work well with a secondary lean or split top. I try to leave all my butt ends facing the same direction, the road. This guy would have went down the hollow into the creek with a conventional back cut. Its far from an exact science, but I've done a few, LOL!