Performance Enhancing Bug

I started working on a mini-sized GF gun which I plan to have both an anti-RM and anti-WS component. First, I used Raiko's gun as a base, and then I added Bin Smoothing from Vyper. The problem was, I forgot to change the array type from int to double, so the bins couldn't hold decimal values and got rounded down. One would think that this would have a harmful effect, but it actually had a significantly positive effect on my robot's score against surfers. I thought that maybe the smoothing was too heavy, so I tried lower smooth factors, and I even tried getting rid of the smoothing altogether, but I still couldn't replicate the score increase.

Any ideas why this happened? Could it be something about the decay rate instead of the smoothing? Has anyone else ever noticed this?