Hi everyone,
I am trying to understand how the use of "cross-control" rudder within a vertical scissor maneuver helps to move your lift vector behind your opponents as noted by this post.
http://bbs.hitechcreations.com/smf/index.php/topic,184939.msg3353011.html#msg3353011
While I'm not questioning this as fact, I have spent the last 10 minutes with my hands as planes trying to see where and when to use rudder and how it changes the lift vector! I`m sure im missing something simple but its just not clicking 
If anyone can explain this in a way my feeble mind might be able to understand I would be most grateful
Many Thanks
Cross-controlling drastically increases drag, so slows you down quicker. Depending upon your orientation vs. the orientation of your opponent, it could also be used to allow your opponent to pull out in front of you... It doesn't really move yours "back", it just slows you down...
It puts your plane into a skid.
It can also "open up" your turns and rolls. That can be beneficial
or detrimental, depending upon the situation. If your inside wing is stalling and threatening to drop, a touch of opposite rudder can potentially delay that (at the expense of widening your turn and bleeding more energy faster; potentially setting you up for an even worse stall a few seconds later. Nothing is free).
Personally, I fly the F4U's almost exclusively, and use the rolling scissors as a go-to maneuver for MANY of my kills.
My philosophy is such that I will do everything I can to use the geometry of the maneuver to lag behind my opponent, while keeping every last shred of energy that I can. I do my absolute best to begin in front of my opponent, and allow him to fly past me, but I want to lose the absolute least energy/speed possible. I want to have enough speed so that as he passes he cannot get away. An ideal situation for me is for my opponent to end up in front of me, but in a worse E-state than I have.
So for me, cross-controlling is almost always undesirable.
Many pilots will try to rapidly slow down and allow their opponent to fly past with a higher speed. I try NOT to slow down. I slow down anyway of course, but do my best not to. I "use" the fact that my opponent
thinks I'm trying to slow down to my benefit.