The answer to the question in the subject line may be found here, for example. Michy calls the 22pt anchor the "butterfly anchor" and his advice, roughly speaking, is to run off it when you can't improve your forward position. Here, there is something you can do to improve your forward position, namely slotting your 4pt. But of course it's also important to take into account your opponent's timing; see the variant below.
          
 
          
 | | White is Player 2
score: 0
pip: 138 | | Unlimited Game | pip: 147
score: 0
Blue is Player 1 |
|
| XGID=--a--BDBBb--bC---b-dc-Ba--:1:1:1:63:0:0:0:0:10 |
| Blue to play 63 |
| 1. | Rollout1 | 13/4 | eq: +0.332 |
| Player:
Opponent: | 53.43% (G:17.28% B:0.72%)
46.57% (G:11.82% B:0.43%) | Conf.: ± 0.010 (+0.322...+0.343) - [100.0%]
Duration: 4 minutes 44 seconds |
|
| 2. | Rollout1 | 13/7 6/3 | eq: +0.294 (-0.038) |
| Player:
Opponent: | 52.20% (G:16.78% B:0.66%)
47.80% (G:12.09% B:0.47%) | Conf.: ± 0.010 (+0.284...+0.304) - [0.0%]
Duration: 4 minutes 47 seconds |
|
| 3. | Rollout1 | 22/13 | eq: +0.176 (-0.156) |
| Player:
Opponent: | 50.67% (G:12.11% B:0.57%)
49.33% (G:15.65% B:0.27%) | Conf.: ± 0.009 (+0.168...+0.185) - [0.0%]
Duration: 4 minutes 40 seconds |
|
| |
1 1296 Games rolled with Variance Reduction.
Dice Seed: 62908879
Moves: 3-ply, cube decisions: XG Roller
|
eXtreme Gammon Version: 2.19.211.pre-release
Variant:
| | White is Player 2
score: 0
pip: 146 | | Unlimited Game | pip: 147
score: 0
Blue is Player 1 |
|
| XGID=--a--BDBBb--cC---b-db-Ba--:1:1:1:63:0:0:0:0:10 |
| Blue to play 63 |
| 1. | XG Roller++ | 22/13 | eq: +0.328 |
| Player:
Opponent: | 55.03% (G:13.17% B:0.52%)
44.97% (G:11.73% B:0.24%) | |
|
| 2. | XG Roller++ | 13/4 | eq: +0.326 (-0.002) |
| Player:
Opponent: | 52.75% (G:17.64% B:0.58%)
47.25% (G:10.90% B:0.39%) | |
|
| 3. | XG Roller++ | 13/7 6/3 | eq: +0.303 (-0.025) |
| Player:
Opponent: | 52.24% (G:17.11% B:0.53%)
47.76% (G:11.04% B:0.39%) | |
|
eXtreme Gammon Version: 2.19.211.pre-release