XGID=--aCCBB----a-------a-ccdb-:1:1:1:42:0:0:0:0:10
X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| | | O O O O O |
| | | O O O O |
| | | O O O |
| | | O |
| | | |
| |BAR| |
| | | |
| | | |
| | | X X | +---+
| | | X X X X | | 2 |
| O | | X X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 43 O: 74 X-O: 0-0
Cube: 2, X own cube
X to play 42
On BGOnline, this sort of position came to be known as a "Bagai
position" because Jeremy Bagai posted a few striking examples of
this type of decision from his own games. But what do I mean by
"this type of decision"? I don't think there exists an "official"
definition of a "Bagai position," but I think of it as a checkerplay
decision with all of the following features:
1. It's a bearin or bearoff play with contact.
2. There's a choice between a safe play and a bold play.
3. The bold play breaks a high home-board point to make a low
home-board point, often hitting in the process.
Among the posts that I copied from BGO to my own website are a bunch
of "Bagai positions" (though not all of them adhere strictly to the
definition above). Here's the link again:
http://timothychow.net/fun.html#sticksforum
Usually (though again, not always), there is a win/gammon tradeoff,
with the "obvious" safe play winning more games, but the bold play
winning more gammons. That is the case here; the DMP play is the
"obvious" 4/off 3/1, but according to XG, either 6/2* 4/2 or 6/2*/off
wins enough extra gammons to justify the boldness.
1. Rollout¹ 6/2* 4/2 eq:+1.090
Player: 88.51% (G:16.06% B:0.40%)
Opponent: 11.49% (G:0.00% B:0.00%)
Confidence: ±0.006 (+1.084..+1.096) - [92.4%]
2. Rollout¹ 6/2* 2/Off eq:+1.084 (-0.006)
Player: 89.00% (G:13.81% B:0.49%)
Opponent: 11.00% (G:0.00% B:0.00%)
Confidence: ±0.005 (+1.079..+1.090) - [7.6%]
3. Rollout¹ 4/Off 3/1 eq:+1.046 (-0.044)
Player: 97.19% (G:6.65% B:0.11%)
Opponent: 2.81% (G:0.00% B:0.00%)
Confidence: ±0.003 (+1.044..+1.049) - [0.0%]
4. Rollout¹ 6/4 6/2* eq:+1.029 (-0.062)
Player: 89.13% (G:9.43% B:0.26%)
Opponent: 10.87% (G:0.00% B:0.00%)
Confidence: ±0.007 (+1.022..+1.035) - [0.0%]
5. Rollout¹ 5/3 5/1 eq:+1.020 (-0.070)
Player: 96.82% (G:4.20% B:0.06%)
Opponent: 3.18% (G:0.00% B:0.00%)
Confidence: ±0.002 (+1.018..+1.022) - [0.0%]
6. Rollout¹ 6/Off eq:+1.010 (-0.081)
Player: 91.58% (G:6.15% B:0.12%)
Opponent: 8.42% (G:0.00% B:0.00%)
Confidence: ±0.005 (+1.005..+1.014) - [0.0%]
¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
eXtreme Gammon Version: 2.19.207.pre-release
---
Tim Chow
--- SoupGate-Win32 v1.05
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