a simple simulation of a baseball game using on-base average as an input

baseball_sim.py

import random

def at_bat(hitter):
  if (random.random() < hitter['avg']):
    return 'ON'
  else:
    return 'OUT'


def inning():
  global hitters, runs, next_batter
  outs = 0
  ob = 0
  while (outs < 3):
    if (at_bat(hitters[next_batter])=='ON'):
      ob+=1
      if (ob>=4):
        ob=3
        runs+=1
    else:
      outs+=1
    next_batter+=1
    next_batter=next_batter%9


hitters = {}
runs = 0
next_batter = 0

def game():
    for i in range(9):
        inning()
    r = runs
    reset()
    return r



def reset():
    global runs, next_batter
    runs = 0
    next_batter = 0


def simulate(games):
    return sum([game() for i in range(games)])/games


hitters = [dict(avg=0.3) for i in range(9)]

# good batter at cleanup
hitters[3]['avg'] = 0.6
simulate(10000)

# good batter at top of order
hitters[0]['avg'] = 0.6
hitters[3]['avg'] = 0.3
simulate(10000)

# good batter last
hitters[8]['avg'] = 0.6
hitters[0]['avg'] = 0.3
simulate(10000)