This video suggests that you engage the chain brake each time you finish a cut, and are moving to do a new cut. That seemed like overkill to me. But yesterday, after I made a cut and took a step back to get ready for a new cut, I tripped and fell backwards. It was no big deal, and I had time to think "Well, the chain isn't moving, so as long as I don't depress the throttle, there is no danger." At that point my left hand automatically and unconsciously came off the front handle to break my fall, and as the front of the saw tilted down, you guessed it, my right hand automatically tightened and depressed the throttle. If you hold out your hands, palm up, and someone drops a book onto them, your muscles will automatically compensate, and it something that happens at the spinal cord level. That is, there's no thought involved, and it happens fast. That's exactly why my right hand squeezed the trigger. The chain only accelerated briefly, and came down harmlessly onto the ground, but it was a perfect illustration of how engaging the chain brake whenever you move around is a good idea. I'm going to try to get into the habit of doing that little hand rotation that switches on the brake after each cut.