abstract sclass AIStrategy<A> implements Steppable {
  F1<A, Double> submit; // returns score
  int round;
  new Best<A> best;
  bool verbose;
  
  void updateBest(A guess, double score) {
    best.put(guess, score);
  }
  
  double submit(A guess) {
    if (guess == null) ret minusInfinity();
    double score = callF(submit, guess);
    best.put(guess, score);
    ret score;
  }
}