how to build a good test bed?

I'm even using thread pool & nio for potentially faster execution. Maybe 5000 roborumble battles should not take 3x time as 1500 tcrm battles, as the rumble contains a lot of easy targets which get destroyed in a second. I'll experiment later.

Btw, my crossover code is not simply doing some gradient descent, but rather do gradient descent or use the weight from one parent directly, based on some random process. Random noise is also added on small probability though. I think this process explores more possible searching space than simply gradient descent + random component. As my experience, the searching space of knn weights is non-trivial, although some pattern exists for most good weights.