Question:
Option 1: bar/23 6/4(2) 23/21
Option 2: bar/23 6/4(2) 24/22
Option 3: bar/23 6/4(2) 13/11
Option 4: bar/23 24/20 13/11
Option 5: bar/23 24/20 6/4
Option 6: bar/23 13/9 (2)
Spoiler
At quasi-gammon-save, I think we need to anchor up. So, bar/23 24/20 for the first three deuces.
At another match score I'd slot the 4 or play off the midpoint, but 23/21 is tempting. Behind in the race against a one point board with an advanced anchor slotting or bringing one down should be sound, and maintaining contact by sitting on the 23 is probably the right idea.
Both 13/11 and 6/4 leave the same numbere of shots (13), but the four point will be more valuable. OTOH, he would like to hit with the runner more than the checker on the 11 and we lose more in the race when hit on the four.
I'll slot the four. 123/21 seems too passive, and if we can make the four we'll have something to show for the risk, while a blot on the 11 doesn't threaten much more than making the bar point with 2 shakes.
bar/23 24/20 6/4
rollout
Spoiler
Anchoring is the right idea, but playing the fourth deuce as 6/4 or 13/11 is unnecessarily risky. The stolid 23/21 is best according to XG.
However, a 1296 rollout does not distinguish it from the Herd's play, which wins quite a few more games while losing quite a few more gammons.
XGID=-a---BD-B-a-dD---bbeA---AA:1:1:1:22:4:1:0:5:10
X:Player 1 O:Player 2
Score is X:4 O:1 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X O O | | O X X |
| X O O | | O |
| X | | O |
| X | | O |
| | X | O |
| |BAR| |
| | | |
| O | | X |
| O | | X | +---+
| O X | | X X | | 2 |
| O O X | | X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 171 O: 151 X-O: 4-1/5
Cube: 2, X own cube
X to play 22
1. Rollout¹ Bar/21 24/20 eq:-0.166
Player: 47.94% (G:10.00% B:0.73%)
Opponent: 52.06% (G:5.97% B:0.50%)
Confidence: ±0.006 (-0.173..-0.160) - [93.3%]
Duration: 6 minutes 22 seconds
2. Rollout¹ Bar/21 6/4(2) eq:-0.173 (-0.007)
Player: 52.20% (G:14.60% B:2.00%)
Opponent: 47.80% (G:10.37% B:1.29%)
Confidence: ±0.007 (-0.180..-0.167) - [6.7%]
Duration: 6 minutes 03 seconds
3. Rollout¹ Bar/23 24/22 6/4(2) eq:-0.189 (-0.023)
Player: 51.44% (G:14.74% B:1.91%)
Opponent: 48.56% (G:10.40% B:1.00%)
Confidence: ±0.007 (-0.196..-0.182) - [0.0%]
Duration: 5 minutes 31 seconds
4. Rollout¹ Bar/23 13/11 6/4(2) eq:-0.228 (-0.061)
Player: 51.02% (G:15.48% B:2.17%)
Opponent: 48.98% (G:11.82% B:1.50%)
Confidence: ±0.007 (-0.235..-0.220) - [0.0%]
Duration: 5 minutes 45 seconds
5. Rollout¹ Bar/23 24/20 6/4 eq:-0.235 (-0.068)
Player: 47.83% (G:11.62% B:0.99%)
Opponent: 52.17% (G:9.12% B:0.85%)
Confidence: ±0.006 (-0.241..-0.228) - [0.0%]
Duration: 6 minutes 39 seconds
¹ 1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
eXtreme Gammon Version: 2.10, MET: Kazaross XG2