Although we typically hesitate to offer any particular implementation as a "solution", we thought it might be informative to see how control structures can be used to avoid any semblence of repetition of code for this project.

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# Demonstration of use of control structures to
# avoid redundancy in Backgammon project
#
# Author: Michael Goldwasser
###############################################


from cs1graphics import *

###############################################
# create initial canvas based on user input
###############################################

size = int(raw_input('How many pixels per "grid" cell? '))
board = Canvas(15 * size, 13 * size, 'burlywood4', 'Backgammon')

###############################################
# add the felt and dividing line
###############################################

for centerX in (4, 11):    # two rectangles, one centered at 4*size, one at 11*size
    felt = Rectangle(6 * size, 11 * size)
    felt.setFillColor('navajowhite')
    felt.move(centerX * size, 6.5 * size)
    felt.setDepth(60)
    board.add(felt)

line = Path(Point(7.5 * size, 0), Point(7.5 * size, 13 * size))
line.setBorderWidth(2)
board.add(line)

###############################################
# There are lots of times that we will need to know the x-value at which
# a "point" on the backgammon board belongs. So let's precompute a list
# so that x[pt] is that value for 1 to 24 (and we'll just leave x[0] as junk)
###############################################
x = [0] * 25
for pt in range(1, 25):
    if pt <= 12:
        column = pt
    else:
        column = 25 - pt    # so 24->1, 23->2, 22->3, 21->4, ...
    if column >= 7:
        column += 1     # everything on rightside moves over by one due to middle bar
    x[pt] = size * (column + 0.5)    # this is center x-coordinate

###############################################
# add the numbers and triangles
###############################################

for pt in range(1, 25):
    if pt >= 13:
        dy = -1    # orient upward from center (i.e. top of board)
    else:
        dy = +1    # orient downward from center (i.e. bototm of board)

    t = Text(str(pt))
    t.setFontSize(int(round(size / 3.0)))    # scale font based on grid
    t.move(x[pt], size * (6.5 + 6 * dy))
    board.add(t)

    point = Polygon(Point(x[pt]           , size * (6.5 + dy*0.5)),   # tip
                    Point(x[pt] + 0.5*size, size * (6.5 + dy*5.5)),   # rightbase
                    Point(x[pt] - 0.5*size, size * (6.5 + dy*5.5)))   # leftbase
    if (pt % 2 == 1):
        point.setFillColor('darkorange3')
    else:
        point.setFillColor('tan')
    board.add(point)

###############################################
# add the checkers
###############################################

checkScale = 0.9
for num,pt,onTop in ((2,1,True), (5,6,False), (3,8,False), (5,12,True)):
    for dy in (-1, +1):       # top then bottom
        baseY = size * (6.5 + dy * 5.5)
        for c in range(num):
            checker = Circle(checkScale * size / 2)
            checker.move(x[pt], baseY - dy * size * checkScale * (0.5+c))
            checker.setDepth(40)
            if ((dy == -1) == onTop):
                checker.setFillColor('white')
            else:
                checker.setFillColor('black')
            board.add(checker)