I bought Marcelo Garcia's book on the X guard last night. Before I bought it I flipped through and thought I saw several techniques for no gi so I bought it, since I only train no gi. When I got home I cracked it open to see what all it entailed. I was pretty disappointed to see that only 41 of the 80 techniques can be used in no gi. (Every technique can be used with the gi by the way.) Only 22 of the 41 are for the x guard. Even the ones that do apply to no gi seem more for just grappling than mma. The rest of the 41 are actually for the butterfly guard which is also included in the book. The x guard (on first look) seems a lot like you are just sitting halfway through the electric chair sweep, but I can't say that it is inneffective as I haven't even had a chance to try it yet, but it does look that way. I just wanted to let everyone out there what to expect with this book so you are more informed before you buy. Looks effective for gi, for no gi.... not so much. Edit: Marcelo Garcia's story is very interesting and if you are really a big fan of his you may just want the book for that. He tells of how he dropped out of school to live a life of Jiu Jitsu, pretty fun story overall. And I meant that I don't think it looks effective for MMA, not no gi grappling. As the poster below has said, he did use the xguard to defeat some very high profile opponents.