PongSim.py

#!/bin/env python

import random
from sys import argv
from functools import reduce
from collections import Counter


class PongSim:
    skills = [[0,0],[0,0]]

    def __init__(self, team1, team2):
        self.skills[0] = team1
        self.skills[1] = team2

    def run_match(self, rollback=True, cups=10, rebuttal=False, rebuttal_team=0):
        cups_left = [cups,cups]
        num_rounds = 0

        if rebuttal:
            second = rebuttal_team
            first = 1 if second == 0 else 0
        else:
            first = random.choice([0,1])
            second = 1 if first == 0 else 0

        while cups_left[0] > 0 and cups_left[1] > 0:
            if num_rounds == 0 and not rebuttal:  # Very first turn only the best player shoots
                if random.random() < max(self.skills[first]):
                    cups_left[first] -= 1
            else:
                teams = [first, second] if num_rounds > 0 else [second]  # Only run sim for second team on first round
                for team in teams:
                    made1 = random.random() < self.skills[team][0]
                    made2 = random.random() < self.skills[team][1]

                    if made1: cups_left[team] -= 1
                    if made2: cups_left[team] -= 1
                    if rollback and made1 and made2 and cups_left[team] > 0:
                        if random.random() < max(self.skills[team]):
                            cups_left[team] -= 1
                    if cups_left[team] < 1:  # we have a winner, do rebuttal here
                        break

            num_rounds += 1

        on_rebuttal = 1 if cups_left[1] > 0 else 0
        winner = self.run_rebuttal(cups_left[on_rebuttal], on_rebuttal)
        return winner

    def run_rebuttal(self, cups_left, team):
        first = max(self.skills[team])
        second = min(self.skills[team])
        round = 1
        while cups_left > 0:
            made = random.random() < [first,second][1%round]
            if made:
                cups_left -= 1
                round += 1
            else:
                break

        if cups_left > 0:
            return 1 if team != 1 else 0
        else:
            return self.run_match(True, 3, True, team)

if __name__ == "__main__":
    game = PongSim([float(argv[2]), float(argv[3])], [float(argv[4]), float(argv[5])])

    num_games = int(argv[1])

    outcome = []
    for i in range(num_games):
        outcome.append(game.run_match())

    winners = Counter(outcome)

    print("{} Games Simulated: Team 1 wins {} times ({}%), Team 2 wins {} ({}%).".format(num_games,
                                                                                         winners[0], winners[0]/num_games,
                                                                                         winners[1], winners[1]/num_games,))