From Walter Trice's book "Backgammon Bootcamp", this is Jeff Ward's method of counting EPC, Effective Pip Count
1) Count the pips
2) Add 2 for each extra checker on the board
3) Add 2 for each extra checker more than 2 on the ace point
4) Add 1 for each extra checker more than 2 on the deuce point
5) Subtract 1 for each extra point in the homeboard
6) Add 0.5 for any checkers in the outfield
See if you can count these 4 examples. Click the picture for results
Also from Walter Trice's book "Backgammon Bootcamp", now that we know how to count our pips, when should we double and when should we take/drop ?
1) If leaders pipcount is LESS than 62
Subtract 5 from the total and divide by 7 (round down)
2) If leaders pipcount is MORE than 62
Take 10% and round it off UP and then add 1
3) If leaders pipcount IS 62 both 1 and 2 adds to the same
1) Leaders pipcount is 45
45 - 5 = 40 / 7 (rounded off down) = 5
Trailer can take if his pipcount is 50 (45+5) and has to drop at 51
2) Leaders pipcount is 87
10% of 87 rounded up is 9 + 1 = 10
Trailer can take at 97 (87+10) but has to drop at 98
3) Leaders pipcount is 115
10% of 115 rounded up is 12 + 1 = 13
Trailer can take at 128 (115+13) but has to drop at 129
4) Leaders pipcount is 28
28 - 5 = 23 / 7 rounded off down is 3
Trailer can take at 31 (28+3) but has to drop at 32
ESTIMATING GAMMONS, BY KÅRE ARONSSON
You have started to prime and you have one of your oppenents men on the bar and you wish to calculate how many % gammons and wether or not to play on for gammon or double for the single point.
1) Count the pips it takes for your opponent to bring all his checkers into his homeboard (not counting the one on the bar)
2) Subtract 5 from the number you get
3) Multiply by 2 .5
1) Grey has checkers on 17+16+7 that need to get to the 6p means 11+10+1 steps = 22
Subtract 5 = 17 multiply by 2 .5 = 42 .5% Gammons
2) Grey has 6+5+4+3+2+1 steps to go = 21 - 5 = 16 * 2 .5 = 40% Gammons
3) Grey has 6+1 step to get all his checkers (besides the one on the bar) in. (6+1-5)*2 .5 = 5% Gammons
4) Grey has 7+6+1 step to go = 14-5 = 9... 9 * 2 .5 = 22 .5% Gammons
Obviously your own position, the score, the strength of the opponent, the likelyhood of getting a WRONG take/drop all comes into account as well but this is a good way to estimate gammonchances
Memorizing the entire table can be difficult. Neil Kazoross developed a simple way to calculate most of the figures without a lot of memorization, called "Neil's Numbers".
The numbers on top represent the number of points the trailer has to go.
The numbers on bottom represent what each point the leader is leading is worth over 50%.
For example, suppose you are ahead 5-away 8-away.
The trailer has 8 points to go, and Neil's number for 8 is 6 (the number below the 8 in the table).
The difference in the scores is 3. So, multiply 3 * 6 = 18, add to 50%, and you come up with 68%.
If you check Woolsey/Heinrich match equity table, you will see that the equity for being ahead 8-away, 5-away is 68%.
If there is no number in the table, do the appropriate interpolation.
For example, suppose you are ahead 3-0 in a 7 point match.
The trailer has 7 points to go, so each point of lead is worth 6 1/2 points over 50% to you -- thus your equity is about 69 1/2% (my table says 70%).
Suppose you are ahead 8-away 12-away.
There is no number for 12, but it is 1/4 of the way between 11 and 15, and the numbers for these are 5 and 4.
Therefore we can interpolate and use 4 3/4. The difference in the scores is 4, so we multiply 4 * 4 3/4 = 19, add to 50%, and get 69%.
This matches the 8-away 12-away entry in my table.
If you happen to be playing a very long match, the table can be extended.
Neil's numbers are: 19 is 3 1/2, and 25 is 3.
Remembering Neil's numbers is easy. The first four entries are trivial.
After that, all you need to remember is the phrase "8 is 6, 11 is 5, 15 is 4", and you've got it.
For most scores, using Neil's numbers will either match or come within one percent of the entry in the match equity table.
Neil's numbers are incredibly accurate if the leader has 3 or more points to go.
However, if the leader has one or two points to go, Neil's numbers do not give accurate results.
It is recommended that you memorize the equities when the leader has one or two points to go, and use Neil's numbers for other scores.