That #13 place was a stream of lucky battles. Ran some more battles later and the rating kept oscilating between 1485 and 1525.
You can also choose whom to fight against and manipulate your rating by choosing only opponents with high PBI, but I avoided it.
My impressions of FightCode:
The API is simpler than "extends Robot" in Robocode.
No energy drop when firing and the gun and bullets are still invisible to radar. So, no way to detect incoming bullets. But you can assume a bunch of tick-head-on bullets.
No independent radar axis, the radar is always pointing to the same direction the gun is.
No velocity and heading in scans, making even linear targeting a challenge.
No "scan()" method, making bots miss a lot of scans, even when there is a sitting duck in front of their guns. I had to hack Walls code a bit to improve scans, but it is still missing a lot of them. And it is a key strategy in Walls to avoid being crushed by opponents close to walls, like Corners.
I wonder how a rambot will perform there. Since it is hard to keep track of opponents due to limited radar, and the only thing which works together with "ahead()" is "fire()", a bot moving and shooting straight forward can do a lot of damage.