fourth_down

import nflgame
year, week = 2015, 7
games = nflgame.games(year=year, week=week)
plays = nflgame.combine_plays(games).filter(fourth_down_att=True)

attempts = 0
att_converted = 0
att_failed = 0

for play in plays:
    attempts += play.fourth_down_att
    att_converted += play.fourth_down_conv
    att_failed += play.fourth_down_failed

print 'Fourth down attempts, week {} {}'.format(week, year)
print 'Total attempts: {}'.format(attempts)
print 'Successful attempts: {:2} ({:.2f}%)'.format(att_converted, float(att_converted)/attempts*100)
print 'Failed attempts: {:2} ({:.2f}%)'.format(att_failed, float(att_failed)/attempts*100)

Fourth down attempts, week 7 2015
Total attempts: 19
Successful attempts:  6 (31.58%)
Failed attempts:  13 (68.42%)