# bayes9_fix

 Author pyfex Submission date 2011-07-05 17:05:57.250815 Rating 7607 Matches played 4364 Win rate 79.61

Use rpsrunner.py to play unranked matches on your computer.

## Source code:

``````# See http://overview.cc/RockPaperScissors for more information about rock, paper, scissors
# Fix a probable bug in the counter_prob function

from collections import defaultdict
import operator
import random

if input == "":
score = {'RR': 0, 'PP': 0, 'SS': 0, 'PR': 1, 'RS': 1, 'SP': 1,'RP': -1, 'SR': -1, 'PS': -1,}
cscore = {'RR': 'r', 'PP': 'r', 'SS': 'r', 'PR': 'b', 'RS': 'b', 'SP': 'b','RP': 'c', 'SR': 'c', 'PS': 'c',}
beat = {'P': 'S', 'S': 'R', 'R': 'P'}
cede = {'P': 'R', 'S': 'P', 'R': 'S'}
rps = ['R', 'P', 'S']

def counter_prob(probs):
weighted_list = []
for h in ['R', 'P', 'S']:
weighted = 0
for p in probs.keys():
points = score[h+p]
prob = probs[p]
weighted += points * prob
weighted_list.append((h, weighted))

return max(weighted_list, key=operator.itemgetter(1))[0]

played_probs = defaultdict(lambda: 1)
opp_probs = defaultdict(lambda: defaultdict(lambda: 1))
my_probs = defaultdict(lambda: defaultdict(lambda: 1))
both_probs = defaultdict(lambda: defaultdict(lambda: 1))

opp2_probs = defaultdict(lambda: defaultdict(lambda: 1))
my2_probs = defaultdict(lambda: defaultdict(lambda: 1))
both2_probs = defaultdict(lambda: defaultdict(lambda: 1))

win_probs = defaultdict(lambda: 1)
lose_probs = defaultdict(lambda: 1)
tie_probs = defaultdict(lambda: 1)

opp_answers = {'c': 1, 'b': 1, 'r': 1}
my_answers = {'c': 1, 'b': 1, 'r': 1}

opp2_answers = {'c': 1, 'b': 1, 'r': 1}
my2_answers = {'c': 1, 'b': 1, 'r': 1}

patterndict = defaultdict(str)
patterndict2 = defaultdict(str)

csu = [0] * 6 # consecutive strategy usage
csc = []  # consecutive strategy candidates

output = random.choice(["R", "P", "S"])
hist = ""
my = opp = my2 = opp2 = ""
sc = 0
opp_strats = []
else:
previous_opp_strats = opp_strats[:]
previous_sc = sc

sc = score[output + input]
for i, c in enumerate(csc):
if c == input:
csu[i] += 1
else:
csu[i] = 0

m = max(csu)
opp_strats = [i for i, c in enumerate(csc) if csu[i] == m]

if previous_sc == 1:
for s1 in previous_opp_strats:
for s2 in opp_strats:
win_probs[chr(s1)+chr(s2)] += 1

if previous_sc == 0:
for s1 in previous_opp_strats:
for s2 in opp_strats:
tie_probs[chr(s1)+chr(s2)] += 1

if previous_sc == -1:
for s1 in previous_opp_strats:
for s2 in opp_strats:
lose_probs[chr(s1)+chr(s2)] += 1

if my and opp:
if my2 and opp2:

for length in range(min(10, len(hist)), 0, -2):
pattern = patterndict[hist[-length:]]
if pattern:
for length2 in range(min(10, len(pattern)), 0, -2):
patterndict2[pattern[-length2:]] += output + input
patterndict[hist[-length:]] += output + input

played_probs[input] += 1
opp_probs[opp][input] += 1
my_probs[my][input] += 1
both_probs[my+opp][input] += 1

opp2_probs[opp2][input] += 1
my2_probs[my2][input] += 1
both2_probs[my2+opp2][input] += 1

hist += output + input

my = opp = my2 = opp2 = ""

for length in range(min(10, len(hist)), 0, -2):
pattern = patterndict[hist[-length:]]
if pattern != "":
my = pattern[-2]
opp = pattern[-1]
for length2 in range(min(10, len(pattern)), 0, -2):
pattern2 = patterndict2[pattern[-length2:]]
if pattern2 != "":
my2 = pattern2[-2]
opp2 = pattern2[-1]
break
break

probs = {}
for hand in rps:
probs[hand] = played_probs[hand]

if my and opp:
for hand in rps:
probs[hand] *= opp_probs[opp][hand] * my_probs[my][hand] * both_probs[my+opp][hand]

csc = [opp, beat[opp], cede[opp], my, cede[my], beat[my]]

strats_for_hand = {'R': [], 'P': [], 'S': []}
for i, c in enumerate(csc):
strats_for_hand[c].append(i)

if sc == 1:
pr = win_probs
if sc == 0:
pr = tie_probs
if sc == -1:
pr = lose_probs

for hand in rps:
for s1 in opp_strats:
for s2 in strats_for_hand[hand]:
probs[hand] *= pr[chr(s1)+chr(s2)]
else:
csc = []

if my2 and opp2:
for hand in rps:
probs[hand] *= opp2_probs[opp2][hand] * my2_probs[my2][hand] * both2_probs[my2+opp2][hand]