[Groundhog]

I decided to put my theory behind how an actual possession would work to the test, and put together a quick proof of concept for a possession. The theory would be that each play would be a loop. A variable would be used to progress through the play, with each step pointing to the next step that would be called... In the following example I use the 'o' variable to keep the play alive, and the 'i' variable to point the play at the next step each time the loop runs.

This is a simple play that sees the C set a high pick for the PG who, if the screen is a success, will either shoot, pass, or drive:

import random
o = 0
i = ""
while o != 1:
  if i == "":
    #first step of the play
    #offensive player's positions on the court set.
    print "5 man moves to set a high screen for the 1"
    #subtract time from game clock and shot clocks.
    i = 1
  elif i == 1:
    #second step of the play
    #offensive player's positions on the court set.
    #calculate the success of the screen and/or any fouls.
    screensuccess = random.randrange(0,2)
    #subtract time from game clock and shot clocks.
    if screensuccess == 0:
      print "5 man sets a bad screen."
      i = 99
      #set a game-state variable that would mean the next possession
      #is a 'broken play' with the ball in the PG's hands.
    else:
      print "1 runs off the pick by 5 man"
      i = 2
  elif i == 2:
    #third step of the play
    #offensive player's positions on the court set.
    #check for turnover by ballhandler.
    #determine if ball handler goes to the basket, shoots, or passes.
    #subtract time from game clock and shot clocks.
    pgdecision = random.randrange(0,3)
    if pgdecision == 0:
      #final step of play.
      #offensive player's positions on the court set.
      #check for turnover by ballhandler.
      #subtract time from game clock and shot clocks.
      print "1 drives to the basket."
      i = 99
      #set a game-state variable that would mean the next possession
       #is a drive by the current ballhandler.
    elif pgdecision == 1:
      #final step of play.
      #offensive player's positions on the court set.
      #check for turnover by ballhandler.
      #subtract time from game clock and shot clocks.
      print "1 pulls up for the long jumper"
      i = 99    
      #set a game-state variable that would mean the next possession
      #is a jumpshot by the ballhandler.
    elif pgdecision == 2:
      #final step of play.
      #offensive player's positions on the court set.
      #check for turnover by ballhandler.
      #subtract time from game clock and shot clocks.
      print "1 passes to a teammate"
      i = 99
      #set a game-state variable that would mean the next possession
      #is a 'broken play'.
  elif i == 99:
    o = 1
    i = ""

The end result:

5 man moves to set a high screen for the 1
1 runs off the pick by 5 man
1 pulls up for the long jumper

I run it a bunch of times to make sure the results are random, and it looks good! Obviously there would be a lot more complexity involved in the final version - ie. not straight random decisions, but based on tactics and attributes. But it's a start.