I played with Rubber guard for the first time in gi last night. Mind you, it wasn't REALLY the first time, but it was the first time after I'd properly learned mission control to zombie to New york. (s/o to Josh at 10p Chicago for letting me drop in and breaking it down. You guys are beasts. It was an honor and I can't wait for the next time). I have a slightly different perspective than the post above. I found zombie to be WAYYYY easier to achieve in gi. While it is true that the gi adds a lot of friction, this is more amplified in his inability to rip his arm out than it is for you to achieve the zombie. For good measure, there appear to be things you could do with the lapel and sleeve, but let's not get into that habit too much. What I found to be effective is using some 'gi' principles to break the guys posture allowing you to get to mission control. In short, I think rubber guard in gi can be extremely, extremely effective if you properly balance out using gi and no-gi principles as appropriate. This would obviously be multiplied if the guy doesn't know what you're doing. No one at my school really plays 10p game except for one or two dudes, but I'd imagine zombie would be harder to achieve if the guy were anticipating it. But friction can definitely be your friend, as long as you don't let him grab your lapels for stabilization. To be fair, it'll most likely take years of heefer to properly break down and dissect rubber guard in gi to the degree and level of sophistication that it's already been broken down in no-gi. All part of the fun, I guess