In my opinion, this method is more work than it's worth for longer races (when no one has borne off yet) and when both sides have little wastage. The method seems most appropriate where you have Pips versus Rolls. Then you convert both sides to EPC and apply the racing rules from there.
EPC is widely known and can be found in Trice's excellent book Backgammon Boot Camp. The online article at bkgm.com (http://www.bkgm.com/articles/EffectivePipCount/) also covers most of the concepts.
Wastage Basics
For a Pips position: EPC = Pip Count + estimated Wastage
1. Nice positions waste 7 pips (the 7-5-3 position). Note pretty much any configuration where all checkers are on 4-5-6 points are 7 pips wastage.
1a. Nice with 7-8 checkers remaining is 6.5 pips wastage
1b. Nice with 5-6 checkers remaining is 6 pips wastage
2. Flat positions waste 10 pips (2 each on 1pt thru 6 pt)
3. "1/2 flat" wastes 6 pips (1 each on 1pt thru 6 pt)
4. Single checker on 4 pt wastes 4 pips
5. Single checker on 10 pt wastes 5 pips
For a Rolls position: EPC = 7N + 1
1. Additions to pip count are necessary when misses are possible. (ie when not all checkers are on ace and deuce point). Use table below to estimate additional wastage to 7N + 1.
Even and Odd columns represent the average pip count per checker when there are Even or Odd number of checkers remaining to bear-off.
So if you had even number of checkers left and average pip was 2.6, then you would add 3 pips to the 7N + 1 calculation.
| Add | Even | Odd |
|---|---|---|
| 1 | 2.0 | 2.6 |
| 2 | 2.3 | 2.9 |
| 3 | 2.6 | 3.2 |
| 4 | 2.8 | 3.4 |
| 5 | 3.0 | 3.6 |
2. Stack & Straggler (1 straggler). EPC = 3.5c + p
3. Stack & Straggler (2 stragglers). EPC = 3.5c + p1 + p2 - 4
where ...
c is number of checkers remaining
p is pip count of the straggler
Application / EPC Racing Formula
Point of Last Take = (# of Rolls to go) - 3
Note: # of Rolls to go can be approximated as EPC / 7 (round down)
Double within 2 pips of last take
Redouble within 1 pip of last take
*** This breaks down when you get to 3 rolls or less ***
*** So you need to use other methods when EPC in low 20's or about 4 checkers per side ***
Practice / Prop 57
Stick recommended using Trice's Prop 57 as practice estimating wastage and using the EPC racing formula.
Here are a few sample positions taken from practice versus XG .
 is XG Roller+score: 0 pip: 19 | ||||||||||||||||
 | Unlimited Game Jacoby Beaver | |||||||||||||||
| pip: 38 score: 0  is Player 1 | ||||||||||||||||
| XGID=-----DC---------------bde-:0:0:-1:00:0:0:3:0:10 | ||||||||||||||||
| on roll, cube action? | ||||||||||||||||
| Analyzed in XG Roller+ | No double | Double/Take |
| Player Winning Chances: | 72.27% (G:0.00% B:0.00%) | 72.17% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 27.73% (G:0.00% B:0.00%) | 27.83% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.445 | +0.887 |
| Cubeful Equities | ||
| No double: | +0.714 (-0.072) | |
 Double/Take: | +0.786 | |
| Double/Pass: | +1.000 (+0.214) | |
| Best Cube action: Double / Take | ||
eXtreme Gammon Version: 2.01
So XG's EPC is 6 roll position or 43.
Last take is 43/6 -3 or 3 pips.
So I need to have EPC of 46 or less to take.
I have 38 + wastage. Wastage for nice position with 7-8 checkers left is 6.5. I have a gap on the 4 pt which must be a bit worse than "nice" but I am at 44.5 so far so must be easy take. Turns out the penalty is only .2 so the take is "super-easy" but how easy would it be to estimate this without the practice?
| is XG Roller+ score: 0 pip: 26 | ||||||||||||||||
| | Unlimited Game Jacoby Beaver | |||||||||||||||
| pip: 41 score: 0 is Player 1 | ||||||||||||||||
| XGID=--A-CCB---------------ded-:0:0:1:00:0:0:3:0:10 | ||||||||||||||||
| on roll, cube action? | ||||||||||||||||
| Analyzed in XG Roller+ | No double | Double/Take |
| Player Winning Chances: | 72.63% (G:0.00% B:0.00%) | 72.64% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 27.37% (G:0.00% B:0.00%) | 27.36% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.453 | +0.906 |
| Cubeful Equities | ||
| No double: | +0.682 (-0.083) | |
| Double/Take: | +0.765 | |
| Double/Pass: | +1.000 (+0.235) | |
| Best Cube action: Double / Take | ||
eXtreme Gammon Version: 2.01
I missed the cube here.
I have 41 + wastage of about 7 for 48 EPC. 48/7 - 3 is 3 so last take is 51 for XG.
I show XG with 7 roll position or EPC of 50.
I got confused on interpreting the cube action. Since last take is 51 I should double if XG has 49 or more... ie, within 2 pips of last take. XG gas 50 so proper action is Double/Take as the analysis shows.
Clearly I need more practice, especially since I was doing this as an "open notes" exercise.
| is XG Roller+ score: 0 pip: 40 | ||||||||||||||||
| | Unlimited Game Jacoby Beaver | |||||||||||||||
| pip: 25 score: 0 is Player 1 | ||||||||||||||||
| XGID=-EDD---------------bdb----:0:0:-1:00:0:0:3:0:10 | ||||||||||||||||
| on roll, cube action? | ||||||||||||||||
| Analyzed in XG Roller+ | No double | Double/Take |
| Player Winning Chances: | 76.57% (G:0.00% B:0.00%) | 76.58% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 23.43% (G:0.00% B:0.00%) | 23.42% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.531 | +1.063 |
| Cubeful Equities | ||
| No double: | +0.782 (-0.165) | |
| Double/Take: | +0.947 | |
| Double/Pass: | +1.000 (+0.053) | |
| Best Cube action: Double / Take | ||
eXtreme Gammon Version: 2.01
This is basically the same position but now I am on the Take/Drop side.
XG has 40 + 7 wastage or EPC of 47.
Last Take is 47 + (47/7) - 3 or 50.
I have 7 roll position or EPC of 50.
So proper cube action is Double/Take.
| is XG Roller+ score: 0 pip: 30 | ||||||||||||||||
| | Unlimited Game Jacoby Beaver | |||||||||||||||
| pip: 14 score: 0 is Player 1 | ||||||||||||||||
| XGID=-DE----------------bbb----:0:0:-1:00:0:0:3:0:10 | ||||||||||||||||
| on roll, cube action? | ||||||||||||||||
| Analyzed in XG Roller+ | No double | Double/Take |
| Player Winning Chances: | 67.21% (G:0.00% B:0.00%) | 67.21% (G:0.00% B:0.00%) |
| Opponent Winning Chances: | 32.79% (G:0.00% B:0.00%) | 32.79% (G:0.00% B:0.00%) |
| Cubeless Equities | +0.344 | +0.688 |
| Cubeful Equities | ||
| No double: | +0.523 (-0.014) | |
| Double/Take: | +0.537 | |
| Double/Pass: | +1.000 (+0.463) | |
| Best Cube action: Double / Take | ||
eXtreme Gammon Version: 2.01
Here is another example from the Rolls side.
XG is just barely on the front edge of the doubling window.
XG has 30 + 6 wastage.
Last Take is 36/7 -3 or 2.
So Trailer last take is 38 pips.
I have 5 roll position or 36 so the take is very comfortable.
The Double is also correct since the window opens at 38- 2 pips or 36.
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