Rarely. To find out if they do, visit the league locatoer which someone already gave you the link to. As for "luck of the pack", I've noticed the same thing. I once bought a box worth of packs at half price, and got 0 holos, and 0 X's. I'm not sure how third party packaging works, but the packs aren't fixed, as I have heard many reports of X's in blister/other 3rd-party packs.