Othello Pos 1

 

4PPgICSGZ/ABKA:cIm6ABAAGAAA
XGID=-aBa–DaB—cE—d-e—AA-:0:0:1:56:3:1:0:5:8

Pipcount Black 156  White 165  Black to play 6-5
Score is Black 3 White 1 in a 5 Point Match

Source : http://spbg.sakura.ne.jp/fes2009quiz.html
Forum: http://spbg.sakura.ne.jp/cgi-bin/yybbs.cgi

Comment:

When you have complicated Positions and Rolls to play, its always a good idea to get an Overview of the Position, like Race, Points, Score, Position of the Cube and your overall Gameplan how you plan to win this Game or Match.

Score
First of all lets take a look at the Score Black is 2-away white is 4-away. The most effective way  for Black to win this Match is an undoubled Gammon. White on the other side will use the cube as soon as he has some Gammon Threads,  a Gammon with the Cube on 2 brings White 100% Matchequity hence winning the Match. The Cube is for Black like a dead Cube at this Score, his Double Point is very high, and white would redouble him to 4 at once. The Gammonprice for Black is around 0,74 compared to Money Games where the Gammonprice is 0,5. By only considering the Score Black  should play for a Gammon, and not even thinking about using the Cube at this stage of the game. By the way White´s Gammonprice with the cube centered is only 0,435, even lower as in Moneygames. Conclusion is White is looking to create a gammonish position and double Black, Black is trying to play for Gammon with the Cube centerd. So at this stage the score points forward an aggressive play for Black.

Race
Black has the Racelead here, and 6-5 is the highest non-double rolls available. So after this Roll Black is with 20 pips ahead in the Race. The wastage is a bit higher cause Black has already made his 2 Point. And by the way the 2 point is not realy a nice point at the Beginning of a game, but sometimes you must make it.  Also to consider is that White is with 3 checkers behind, Black with 2.

Position
The Position is clear White has not made any assets so far, its almost like the starting Position on white´s side of the Board. White is looking here to make a good defense, because he is back in the Race, he got the weaker Board. White´s aim is clear he want to make an Anchor, here specially something like the Bar-Point and leaving one Blot behind on the ace point, or the 3 Point-Anchor. Its important for White to stay as far back as possible, white needs a good defense that he can start building his Board. White is looking for something like this:

 

 

 

When White reaches one of the Positons above or similar Defense structure, imagine how difficult it will become for Black to improve his board, it will become quite hard for Black to play against a Defense like the 2 above, specially consider now how weak the 2 Point becomes. Also very important is, that if white manage to build up his defense, Blacks chances to win a gammon drops considerably not only in short over the whole game, also in the long term, the Anochor protects white against loosing a Gammon, and let him take some risks to build his board.
Now lets take look at the Position of Black, well first impression is it looks stronger, but if we go a little deeper its not realy as good as it looks. First of all Black´s 8 pt is stripped, he got a Stack on his midpt, and he has made a deep point in his board. The made 2 point takes away some flexibilty in his Gameplans, its very unlikly for Black to play here for a prime, its more likely for him to go for an Attacking game or Running Game, but prime game is as good as closed out of his plans.

Gameplan
When you consider what we have analyed above about the Position and the score, blacks short time plan is to avoid that white builds up a good defense here, Black is on roll, he got the Power of being on Roll now, and this is big advantage and it increases his winning chance. Because of his already made 2 point we can close out any approach direction prime plan. So now lets go trough the possible different Moves we can play with the 6-5.

Non-Hitting Moves:
13/2 , 23/18 8/2  
well forgot this 2 moves, they kill one more checker an the second one leaves a blot. Big Closeout for these two.

24/18 23/18

 

This one is a very dangerous trap here, imagine you are in the money round of live tournament, or play matches for big amounts and you are on time pressure ( usually they use clocks). What comes in your mind after you analyse the Position, wow iam ahead in the race with 20 pips, iam ahead in the score, this play is safe it makes a good Anchor, not mutch thinking about it, i make it.
This play gives white totally freedom to build up his Defensive, and even if he rolles bad numbers, white can start building his board for example Slotting his 5 or 4 point. And another Point is very important here, with making the Barpoint Anchor Black is aiming forward an Holding Game. First of all Holding Games usually produce less gammon wins, as we know Black is looking to win a Gammon. Second, one short time plan of black is to not let White build up his Defense structure. Just imagine who will play more comfortable the next rolls, Black or White, well of course white, he got totally freedom to build his board and building up his Defense structure. Black on the the other side needs to roll very well to improve his board and making new points, almost every roll is dangerous, once White has made a 3 Point or stronger this Holding game can becomes very uncomfortable for Black to play. And there is the Race and the Timing problem here. In a Holding Game Black will be forced off his Barpoint Anchor much earlier than white, because of his Racelead. This can be fatal for Black, when white has build up a strong Board, I think even a 3 Pt-Board is strong enough for White to double if he gets enough shoots here, specially if black has more than 1 blots around. Also its important for Black to see that there is no thread from White, White doesnt have any Homeboard Points no Priming Thread nothing, so no need to make an Anchor here, the Action is on the other side of the Board.
Finally this cant be the right move here, so lets close it out.

24/18
We can close out this move very fast, its even more dangerous to leave one Blot isolated behind, and all the reasons above apply too here.

Hitting Moves
23/18 13/7*

 

First of all the Hitting plays looks much better than the non Hitting plays, cause it increase the gammon chance, second it take. away in this case here at least half roll of the opp. But what is with our short time plan here to prevent white building up his Defense Structure ?. Well lets go trough the rolls white can have next roll :

1-1, 1-2, 1-3, 1-4, 1-5, 1-6, 2-3, 2-4, 2-5, 3-3, 3-4, 3-5, 3-6, 4-4, 4-5, 4-6, 5-5, 6-5
all these rolls are good for white either he makes an Anchor, or/and  hitting one of the Blots of Black. Count them thats 32 Rolls out of 36.
Only 2-2 , 6-6, 2-6  thats 4 Rolls are realy good for Black but he shouldnt not rely that White will roll so pure.
Because of our Gameplan we can close out this play quite fast, it leaves White too many good Rolls, and in most of the cases White will have a nice Defense structure.

13/8 13/7*

This move is almost the same like the Move before, its a little bit better because Black has moved one more Attacker down from his Midpoint, closer to his Homeboard.  We can close out this one with the same reasons like the Move before.

13/7* 6/1*

This is the Attacking Play going all in for the Close out and taking away whites next roll completly, execpt white rolls  doubles. This move looks much better, cause it take away Whites flexibilty for building up a Defense and it raises the Gammon Chance. But there is something i dont like on this move, its the hit on the Acepoint. If Black fails to carry out his Attack here, Black will have almost 3 semi-dead checkers, and much worse is, if White Rolls a 3 in his next Roll, result would be for Black quite bad, 3 Semi-Dead Checkers, and White has the 3 Point Anchor, which is realy powerful in this Position. It´s the best of the moves we have analysed so far, but lets take a look if we can do it better.

13/7* 8/3*

It´s also a double Hit  but this time we hit the Blot on the 3 pt instead of hitting the Blot on the 1 Point. So whats the difference between this Move and 13/7* 6/1*. First of all the amount of rehits are the same 11 rolls. Black leaves 5 Blots instead of 4, shouldnt make the difference here cause  White is on the Bar with 2 Checkers, and White doesnt have any Board or Prime which Black must be afraid of.
Second Black puts away the dangerous 3´s, which gave White the possibilty to make the 3 pt-Anchor and building up an effective Defense. Instead now White can make the Acept Anchor, which is much more preferable for Black, because the Anchor is behind Blacks 2 pt, some how, we can say Black also now reactivate the Gameplan of Priming, not very strong but if the Attack fails Black has some chance to switch to prime White.
Third point is, that its much easier for Black to cover the Blot on the 3 Point.
Finally this is not realy a Blitz for me, its more like a big tempo Play which, if Black rolls well can end up in a Closeout. Black has only 4 active Attackers close to his Board, and i think, White will end up with an Anchor, in most cases on the Acepoint. It´s the best Play because it raises the Gammon Chance and it prevents White from building up an effective Defense.

Rollouts originally from http://spbg.sakura.ne.jp/fesquiz2009/1.txt

1. Rollout¹ 13/7* 8/3* eq:+0.069
Player : 56.99% (G:27.48% B:9.45%)
Opponent: 43.01% (G:11.89% B:1.50%)
Confidence: ± 0.027 (+0.042<E<+0.096)
Duration: 36 minutes 16 seconds

2. Rollout¹ 13/7* 6/1* eq:-0.049 (-0.119)
Player : 55.06% (G:25.09% B:5.14%)
Opponent: 44.94% (G:12.48% B:1.19%)
Confidence: ± 0.025 (-0.074<E<-0.024)
Duration: 35 minutes 33 seconds

3. Rollout¹ 13/8 13/7* eq:-0.126 (-0.196)
Player : 53.80% (G:22.51% B:5.42%)
Opponent: 46.20% (G:12.20% B:1.46%)
Confidence: ± 0.024 (-0.150<E<-0.102)
Duration: 38 minutes 13 seconds

4. Rollout¹ 23/18 13/7* eq:-0.178 (-0.248)
Player : 53.54% (G:20.00% B:4.48%)
Opponent: 46.46% (G:13.53% B:1.39%)
Confidence: ± 0.025 (-0.203<E<-0.153)
Duration: 38 minutes 21 seconds

5. Rollout¹ 24/18 23/18 eq:-0.180 (-0.250)
Player : 53.76% (G:17.00% B:2.66%)
Opponent: 46.24% (G:13.04% B:0.98%)
Confidence: ± 0.025 (-0.205<E<-0.155)
Duration: 33 minutes 23 seconds

Hope you like my Analyse feel free to leave Comments.

Tomorrow I will work on the 2 Position, maybe tonight.

Good Luck and Good Skill all

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