the dorbel daily

Friday, 8 July 2011

The Themed Quiz. Part One.

I promised you some positions from Mochy v. Melzi, an IIBGF match that I am annotating at present. Four of them, all from the same game.
Blue (Melzi) leads 12-1 to 13 and it's the Crawford game.

White (Mochy) is on roll here and has a 6-1 to play.

Diagram 1

Position ID: 2szgABaYuxswAA

In the next position (diagram 2), Blue is on roll and has a 6-3 to play.

Diagram 2

Position ID: mLs7IADazOAAFg

In diagram 3, Blue is on roll and has a 3-2 to play.

Diagram 3

Position ID: mLt3AAC2NeAAFg

And finally, in diagram 4, Blue to play a 6-1.

Diagram 4

Position ID: se1uAAC2bYQAFg

Do not assume that because this is a quiz, the "obvious" answer can't be right. Stay objective! Make the play that you would make over the board, in a match, although here of course you have the luxury of taking your time. You can even, recommended, set out the pieces on your board and shuffle them around a bit. I'd be pleased to hear your answers in the comments section and your reasoning is much more interesting (to me) than what you decide to play and whether you get it right or wrong. The whole point of this blog is for you and me to learn and the key to improving is to establish a method of looking at a position that gives us a chance to find the answer. The answer itself is much less important than how we arrive at it, because one thing is for sure, you will never see any of these positions again!
Answers please! Until we meet again, enjoy the game!


moonshadow said...

#1 14-9

I look at this as pay now or pay later and white may as well risk leaving a blot on the 16 rather than more than likely eaving one later when blues board is much stronger.

Playing it "safe" and burying a checker on the ace (8-7,7-6) doesn't avoid the problem as it results in a much weaker blockade (leaving 2 checkers on the 8 instead of 3), especially with the open 5 point, and will leave more awkward rolls for white down the line than can't be played without leaving some blots. And by that time, blue will probably have a much stronger inner board, so if a white blot gets hit, it probably won't escape.

Right now the 3 checkers stacked on the 8,7,6 and if my play of 16-9 is followed there will also be 3 checkers stacked on the 9 as well, give optimum chances for white to make the 5 point, point on the blot on the 2 point, or just safely avoid leaving any blots for blue to hit.

I just can't see any other play than 16-9.

moonshadow said...

#2 12-18,17-20

The way i look st this it is that its desperation time for blue, whose only hope is to hit and then contain one of whites blots.

Right now, if white gets hit, blues inner board is weak with a blot on the 2 point and an empty 5 point.

Blues priority is to make the 5 point and then worry about covering the blot on the 2 point.

12-18, 17-20 sets the stage for making the 5 point on the next roll, which is far more important than making the 23. 17-23 would be a blunder as white, if hit, can more easily escape with a 5, whereas if blue does make the 5 point, white will have a much more difficult time escaping from blues inner board.

Running the checker on the 2 to the 10 is the worst play because blue needs a miraculous hit at some point to win the game and stay alive in the match. Running the checker on the 2 over the prime sllows white to safely bury a checker on the 2 without threat of that checker being hit--yes, a small possibility, but blue st this point has to play as if he is going to have a chance to hit something and in order to do that, he is going to have to leave that blot on the 2.

Even if that blot on the 2 eventually gets pointed on, its still worth the risk, especially at at this stage as it doesn't matter if blue gets gammoned or not.

moonshadow said...

#3 13-11,13-10

Blue needs to stay as far back near the acepoint as possible to have a chance at hitting something.

23-20, 22-20 would be a blunder because it will more easily allow white to safely bear in without leaving any blots and blue has to hit a blot to stay alive in the match.

If I were playing to avoid gammon, I would consider 22-20, 23-20 (though even then, I'm not sure)

So that said, my 13-11, 22-20 sets blue up to make the 5 point in his inner board on the next roll, while on the other side of the board leave blue the maximum amount of chances to hit a blot white might leave on the bear in.

moonshadow said...

#4 13-7, 9-8

If I were blue playing to avoid a gammon I would play 23-22.

But gammons here don't matter and for the reasons I gave in #2 above, leaving the checker on the 23 will give blue slightly more chances to hit a possible white blot.

13-7, 9-8 may not be the best play (13-6?) but I don't think it would be the worst so its my choice.

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Julia said...

Agreed 100% with moonshadow. On no. 4 I did toy with 9/2 as an alternative way of hanging on to as many non-destructive ways to play large numbers - White is about to open the back of the prime and we don't want to be forced off the anchor with a 6 until at least some of those builders have been wasted deep in White's board.

ah_clem said...

1) I hit here, and then continue on to the ace point since I don't see a better way to play the ace. White would really like a gammon here, so hit away. The other play I see is to run from the 16 (16/9) but that leaves more shots and doesn't seem to win more games or gammons. 8/2*/1

(Ok, I've now looked at diagram 2 and see that Mochy ran from the 16 - that probably means it's correct to run)

2) RUN! Run like hell. 23/14 Get a checker out of there to preserve timing and minimize gammons. Yes, there are 15 shots and it breaks contact somewhat, but at this match score I'd be playing gammon save.

(And now I've just looked at diagram 3 - obviously the easy way to solve this little quiz is to look at the next diagram to see what the "Giant" did. But I'm not going to do it that way, I'll make my own blunders, thank you.)

3) I'd bring down 2 to aim at the 5 point. Prepping an escape with 23/20 asks for white to whack it, probably even hitting loose. 13/10 13/11

4) I safety the blot on the 23 to minimize gammons. At DMP I'd leave it be. 13/7 23/22

moonshadow said...

A big blunder on my part in that I got so caught up in thinking about #1 where WHITE is on roll and down 1-11 in a 13 pointer, that when I went to look at #2,3,4 my brain leaped to the conclusion that BLUE was actually playing from 1-11 down.