Yes, the mere existence of a gap is not the point. We are trying to minimize EPC, or to minimize wastage. My point is that a good general heuristic for minimizing wastage is to think of checkers on point 2n as (partially) having the job of filling gaps on point n when you roll n.
Below is another random example I generated on the spot. How do we play the 2? It's intuitive that we shouldn't stack up, but do we play 3/1 or 4/2? My heuristic says to play 4/2. It's the same number of gaps either way, but 4/2 leaves us with a lower EPC, and is also the right play.
I'm not saying that the heuristic always works (EPC itself is a heuristic that doesn't always work), but I find that it works often enough to be useful.
       
 
       
 | | White is Player 2
score: 0
pip: 24 | | Unlimited Game | pip: 24
score: 0
Blue is Player 1 |
|
| XGID=---AAAB------------baaa---:1:-1:1:62:0:0:0:0:10 |
| Blue to play 62 |
| 1. | XG Roller++ | 6/Off 4/2 | eq: +0.304 |
| Player:
Opponent: | 67.61% (G:0.00% B:0.00%)
32.39% (G:0.00% B:0.00%) | |
|
| 2. | XG Roller++ | 6/Off 3/1 | eq: +0.288 (-0.016) |
| Player:
Opponent: | 67.00% (G:0.00% B:0.00%)
33.00% (G:0.00% B:0.00%) | |
|
| 3. | XG Roller++ | 6/4 6/Off | eq: +0.274 (-0.030) |
| Player:
Opponent: | 66.31% (G:0.00% B:0.00%)
33.69% (G:0.00% B:0.00%) | |
|
| 4. | XG Roller++ | 6/Off 5/3 | eq: +0.270 (-0.034) |
| Player:
Opponent: | 66.09% (G:0.00% B:0.00%)
33.91% (G:0.00% B:0.00%) | |
|
eXtreme Gammon Version: 2.19.211.pre-release