?????

As for "readability" vs "efficiency", I don't think they are necessarily at odds, besides as they compete for your time and effort. Like Skilgannon said, the most important optimizations are high level stuff - fast code can still be readable, testable, and maintainable. Having everything in one giant method with big ugly lines is not necessarily going to give a huge performance increase.

I think it just so happens that some bots, like DrussGT and Shadow, went through a lot of changes without ever getting sufficiently refactored, so the code is a little disorganized. But the authors made the effort to keep them fast. ;) (In Shadow's case, I'm just going off what ABC has said...) I feel Diamond is decent code and pretty fast. Rednaxela's kd-tree is also good code and lightning fast.