Othello Position 3
October 30, 2009Hi,
here comes the third Position from the Othello Quiz.
Match Black 1 White 3 Matchlength 3
White 123 pips Black 146 pips
jHcHAwjg2zYAMA:cIloAAAACAAA
Black 1-2 to play ?
Source : http://spbg.sakura.ne.jp/fes2009quiz.html
Forum: http://spbg.sakura.ne.jp/cgi-bin/yybbs.cgi
Overview
It´s a Match to 3 Point, Black is 2-away White 3-away. This is an interesting Score, White as the trailer here is looking for gammonish Positions, as soon he comes close to a gammonish Position he will turn the Cube. Overall White is more aggressiv with the Cube at this score, specially he is giving Black a dead Cube. On the other Side Black´s Double point is high here, he need realy good odds to turn the Cube, cause it will redoubled from White to 4 at once, hence DMP. Black as Leader here is very conservative with taking a Double from White here, specially when Gammon Threads in the air.
Position
Black Positions is very unflexible, he got a 5-Prime but a very weak one, with 4 Points stripped and a frontloaded Stack on the 6 Point. He is back with 2 runners, white only with one. Additionaly Black is far behind in the Race with 23 Pips before this Roll. White on the other Side has a more flexible Position, a 3 Prime and a possible Prime from 8 to his 3 Point. White also has alot of Builders and Attackers close to his Board and nice Distributation.
Gameplan
Black´s plan to win this game is quite hard. First of all he must contain the last runner from White, he must somehow makes his Position flexible, he needs to either roll his prime forward or Attacking the single Blot from White, without letting him escape. Additional he needs an better Anchor, cause there is also the danger that he will be primed from White if he stays on the 24 Point. If you ask me, well I dont realy want to be the Black player here in this Position (: . And last but not least he must do this all without giving White a gammonish Positon.
White´s plan is quite easy, if Blacks split Attack and going for a Closeout, if Black doesnt split, White will try to escape his last runner and making his 5 and 4 Point to prime Black´s Anchor on the Acepoint. Now lets examine the possible Moves Black can do.
7/5 6/5
Making the 5 point is always a good idea, and around 99% of the Players would think first of this possibility here. Let´s check weather it fits in our Gameplan for Black.
Black wants to contain the white runner. Before this move White has only the 2-6 to run out, now White has 4-4, 4-5, 4-6 to completly escape the Runner, he got the 4-1, 4-2, 4-3 , 3-1 to run his runner halfway to the Barpoint. Thats 13 good Rolls. And he not only running with this rolls, he is also Hitting. The Risk-Reward here doesnt realy looks well, even if you make the 5 Point. So what you finally do is with 7/5 6/5 is giving White the possibilty to do 2 good thinks Hitting and Running, and this move doesnt helps to contain the white Runner.
Does making the 5 here gives Black more Flexibilty in his Position? Sixes and Fives are not good to play from this Position. 6-2, 6-3 makes the 4 Point, but leaves the gap on the Barpt, which gives White 4´s to run, 5´s are also not realy good to play here. It improves the Flexibility a little bit, but its not enough.
Black wants to avoid gammonish Position, well Black gives White here a direct shoot, and makes it easier for him to escape, hitting here the Blot increases for sure the Gammon wins for White, thats what White is looking for.
Finally we have to consider the Cube here, White has here some Threads, he can escape and hit, and at this Score White should think about sending over a 2 Cube to Black if Black makes the 5 Point. This cant be the right move, even if it is the Golden Point.
10/8 6/5
We can close out very fast this one, it gives 2´s to hit (11 Rolls), 1-6 to escape and hit. Thats again 13 very good Rolls, and the super Joker 2-5 hitting 2 Blots. We can dismiss this move for the same Reason like making the 5 Point. Its a little bit better, cause it moves forward the prime without a gap (4-Prime), and it looks more flexible, but it gives White too many Threads and also a strong Cube. Again as we discussed under Overview, this is exactly what White is looking for.
24/21
24/21 looks much better, because it doesnt make it easier for White to escape, it hold the main asset of Black his 5 Prime. But what is with our other Criteria, like avoiding a gammonish Position. Black has 2 Blots, which are facing 8 Attackers! And white has already made the 3 Point, which is also a good Homeboard Point for Attacking. 8 Attackers close to the Board is realy a high amount for carrying out a Blitz. Again this is exactly what White wants, it cant be the right Move, specially at this Score. Black cannot rely here on his 5 Prime, White has enough Timing to Roll a 2 to come to the Edge of the Prime and escaping his last runner. After this move Black will have a hard decision weather he takes the Double from White.
6/3*
Hitting is allways a good idea if you want to contain your Opponent, at least it takes away his next half Roll, and there is allways the chance that he fans.
But do you realy improve the chance to contain White´s runner here?. With any 5 he enters on the edge of the Prime, Black will be forced to Attack to contain White checker, but now Black has an extra Blot on his 3 Point. 4-1, 3-2 brings White also to the Edge of the Prime. Any 3 hits and 1-2, 1-1 hits. 6-5 Escapes, so as you can see Black after this hit is not realy better then before, instead White has much more chances to come at least at the Edge of the Prime, and he got also some nice Hitting Rolls. The Hit is not realy an improvement, specially it will be much more harder for Black to play his next Rolls, his Prime will be in danger, specially with the Blot on the 3 Point. By the way, Black dont want to make the 3 Point here, he wants to roll forward his Prime, not building Gaps. If Black makes this move, its start of destroying his only asset, his Prime.
6/5 6/4
6/5 6/4 looks realy dangerous, but is it so bad?
First of all its not more easy now for White to escape his runner, still he has only 2-6, or any 2´s to come to the Edge of the Prime.
It keeps his only Asset, his 5 Prime.
It doesnt give White the opportunity to carry out an Blitz on his side of the Board, Black still has the Ace Point Anchor, White now can only Prime the 2 Runners from Black, but not Attack, sometimes an Acepoint Anchor is also good.
Black increases his Flexibiltiy, now he has good 5´s and 6´s to play, covering his 5 and 4 Point, and extending his Prime.
Black is rolling forward his Prime, this is exactly what he wants to do.
The only negative Point is leaving these 2 Blots. But there is also some Duplication involved. 1-3 , 2-4, 2-3 also works well on whites side of the Board. Only realy dangerous is 1-1 and 2-2 and 2-6.
Even if Black gets hit here, he has still the Acepoint Anchor which helps him to save a lot of Gammons. Also after a hit from White, Black has some nice Entering Rolls, which also makes an Advanced Anchor like 5-4, 4-3, 2-1.
Finally we can say that with this double Slot play Black comes much closer to all his Gameplans he has. Its the best move here.
1. Rollout¹ 6/5 6/4 eq:-0.297
Player : 49.56% (G:11.43% B:1.14%)
Opponent: 50.44% (G:20.03% B:5.10%)
Confidence: ± 0.033 (-0.330<E<-0.264)
Duration: 27 minutes 48 seconds
2. Rollout¹ 6/3* eq:-0.441 (-0.145)
Player : 45.50% (G:11.50% B:1.06%)
Opponent: 54.50% (G:18.40% B:3.60%)
Confidence: ± 0.029 (-0.470<E<-0.412)
Duration: 27 minutes 53 seconds
3. Rollout¹ 24/21 eq:-0.452 (-0.156)
Player : 45.98% (G:9.70% B:0.87%)
Opponent: 54.02% (G:19.94% B:1.95%)
Confidence: ± 0.029 (-0.481<E<-0.423)
Duration: 25 minutes 40 seconds
4. Rollout¹ 10/8 6/5 eq:-0.531 (-0.234)
Player : 44.21% (G:10.35% B:1.12%)
Opponent: 55.79% (G:19.83% B:4.10%)
Confidence: ± 0.034 (-0.565<E<-0.497)
Duration: 25 minutes 00 second
5. Rollout¹ 7/5 6/5 eq:-0.562 (-0.266)
Player : 42.81% (G:11.06% B:1.02%)
Opponent: 57.19% (G:17.10% B:3.02%)
Confidence: ± 0.031 (-0.593<E<-0.531)
Duration: 23 minutes 43 seconds
¹ 1440 Games rolled with Variance Reduction.
Moves and cube decisions: 3 ply
