what's the secret to making a good robot in robocode

I'll give you that it assumes a movement profile that scales with bullet flight time. But that's a very light assumption and not the same as assuming orbital. What types of movement don't scale with BFT? Just fixed patterns?

PS: Mathematically, I think bearing offsets would assume bullet power is constant, not BFT, right? ;)

Fixed patterns and bullet dodging movements like enemy fire oscillation.