Dr. Dave seems like a stand up dude...his materials are a bit pricier than Tor's Zero - X stuff. The first Hour of the Zero-x position play video is free on you tube...he also had a 3 hour one on there but in the last six months it has vanished into the Ether...I picked up all of Tor's stuff for 70 bucks so his videos are what I have experience with, if you want to get better and have time to practice these videos will definitely help your knowledge base and improve your game.