Randomized surfing
Well, none of my efforts have been seen in use because I didn't release any of them. :-) But I've tinkered quite a bit, so it's not for lack of trying.
The idea I thought had the most promise involved generating a completely new/random movement profile every time you get hit. Also tried instead/also a new profile every X ticks, or every time a wave passes, or modeling those random stats in a fair number different distributions (flat with flat juice to super spiky), and in various mixes of random + normal flattener. I guess it's possible some of those would've helped against certain bots, but my testing on this is usually restricted to 2-3 strong bots, since the only improvement I'd really care about is beating DrussGT without sacrificing too much vs Shadow/XanderCat. ;)
Well, I'm far less experienced than you guys are. It might not go too well. What I was thinking was that Phantom would track the bullets as precisely as possible, then find a random angle, velocity, and distance to escape them. Sounds a bit like a flattener. Or maybe it will just do BasicSurfer or BasicGTSurfer movement until it dies, then switch to flat movement. Anyway, Phantom may not ever get released. It sounds like implementing this type of movement is pretty difficult.