the dorbel daily

Friday, 25 November 2011

Keeping An Eye On The Masters

On GridGammon I've had the pleasure of watching two superbly played matches between Mochy from Japan and Paul Weaver of the US. I am annotating these and hopefully they will be available in a couple of weeks for students. To whet your appetite here are some cute positions from Match One, Game One.

Position One

Mochy (Black) to play 6-1 from the bar. What should he play?

He played bar/24, 13/7, leaving Paul Weaver White on roll in position 2 below.

Position 2

Should White double?

In the match, he elected to roll and rolled 3-3, correctly playing 24/18*(2). Mochy entered with 4-1 played bar/24, 6/2, probably right, leaving White on roll again in position 3 below.

Position 3

Should White double and if he does, should Black take?

Find out tomorrow! Comments welcome as always. Until then, enjoy the game.


Timothy Chow said...

Tough problems!

1. I would also have played bar/24 13/7. I would not consider 8/2 for more than a moment; bar/18 is the only other reasonable candidate. Black is slightly behind in the race, which normally points to 13/7 over 24/18, aiming to prime rather than escape. Additionally, 24/18 breaks anchor and runs into a double shot at a moment when White's board is stronger.

2. White has 14 shots, but most of them don't lock up the game immediately, and if White misses then White will often find himself in an equal or even inferior priming game. White can make the bar with 66 33 61 but except for White's super-joker 66, these rolls are duplicated with hitting. I wouldn't double.

3. I don't think Black can take this. The question is whether White is too good. I would be tempted to cash this but I have a tendency to cash when too good so I suspect this may be another instance of that. In most cases White will still be able to cash next turn. White has some good rolls that greatly improve his position, and only a few exchanges are bad (e.g., Black manages to hit or roll boxcars next).

Paul likes to joke that he has a pattern of missing a double, rolling a joker, and cashing when too good, thereby winning 1 point instead of 4 points. I wonder if this is a case of that!

Anonymous said...

boop says (can't remember my login at the mo) --- b4 reading other's comments

1) i think i may try bar/24 13/7 like mocky - the only other move is 24/18 which leaves the most hits.

If i'm not hit i'll probably make the 7 point - if i'm hit there are 2 or 3 white blots to get lucky with.

2)umm no double / take? … same reasons as above

3) double / pass - i'll probably make the 8 point very soon giving me better connectivity and black's 2 point blot is vulnerable if I'm unlucky enough to be hit soon.

Anonymous said...

with 3 yes - double and pass - I am not convinced you win enough gammons to continue to play on but will be interested in the analysis