Yeah there's no way to do that stretch with the thumb like I've always placed it in the past. It's just really weird playing with the thumb under the middle of the neck and the wrist all crunched up. I can play it, just not at 299 bpm like they do. Like I said, I don't know if it's worth it to spend 100 hours on one damn riff, but I suppose it will open other doors if I stick with it.