i thought i would share this move that has been working pretty well for me recently.
you use it when you're playing open guard and they manage to pass to your half-guard.
what you do is:
put the point of your knee on their chest. this is sorta like the "z-guard" position: it's half-guard with your knee between you and your opponent, which gives you a lot of space to work with. you just have to be careful that they don't push your knee down and pin it. That's why you cannot put your knee horizontally across their body, but instead must put it at a 45 degree angle (halfway between horizontal and vertical)
the knee is already giving you a lot of space. now all you do is straighten out your body by thrusting your hip forward. This has the effect of pushing you back and pushing them away at the same time. Basically your body is going from folded to straight. The muscles you use to do this are pretty strong. This move is now giving you TONS of space.
now if they are close enough you post with your arms on their head, hip, or body (whatever) and shrimp away, then rotate until they are back in front of you. now you can begin playing your vanilla open guard again.
basically this move has allowed me, when someone has moved off center-axis and is getting close to passing my legs, to put them back at square one. You can either catch their leg in your half-guard as they move around you, or deliberately pull half-guard and then do this move. i love that it lets me play around with open guard and then have a safe manuever to create tons of space and get them back in front of me if i'm in danger of getting passed.
i've been having a good time recently using this move and also roy harris's moves from Andrew Yao's website to just play with people, keeping them from passing my open guard. I find that a lot of people give up base as they attempt to pass and your elevator sweep is right there--you don't even have to look for it, people just fall right in. Also there are a lot of ankle lock and heelhook opportunities here--but I haven't really played with those yet, that's next.
Thnks,
matt