0.014c

Just found why I'm skipping turns so bad —

if (Math.random() < 0.01) {
  ArrayList<Object> list = new ArrayList<>();
  for (int i = 0; i < 10000000; ++i) {
    list.add(new Object());
  }
}

I forgot to comment this out.

Anyway, I think I'm still skipping turns badly when I run two clients together, as a newer version which is theoretically the same as previous version performs much worse.