sclass AIStrategy_RandomWithVariation<A> implements Steppable {
  F0<A> random;
  F1<A> vary;
  F1<A, Double> submit; // returns score
  
  new Best<A> best;
  int round;
  
  public bool step() { go(); false; }
  
  void go {
    A guess = guess();
    if (guess != null)
      best.put(guess, callF(submit, guess));
  }
  
  A guess() {
    A a = null;
    if (odd(round++) && vary != null && best.has())
      a = callF(vary, best!);
    if (a == null)
      a = callF(random);
    ret a;
  }
  
  void updateBest(A guess, double score) {
    best.put(guess, score);
  }
}