the dorbel daily

Wednesday, 27 October 2010

Mochy v. Birkhahn, Game Two (Part 2)

So, taking up where we left off, Red has just redoubled to 4 and White took, leaving the position above.

14. RED: (4 2) 23/21 13/9
Note here how Mochy uses this roll to do two good thing, make a good anchor and diversify his spares on the midpoint. The anchor is insurance against a bad sequence and 13/9 provides another builder for the vital 4pt. Continuing the blitz on this roll with 5/1* would be a big mistake. That builder is needed for the 4pt and the match play allows Red to select one of several game plans as the dice decide.
WHITE: (6 2) bar/23 11/5

This is a sizeable error by Martin. 21/15 is better, taking his chance in the outfield rather than being attacked on the 21pt. If Mochy hits in the outfield, he can't also make the 4pt, except of course with 3-3 which is a huge roll anyway. This is not an isolated case. In general you don't want to be on the point that your oponent wants next when he has builders lined up ready to pounce.
15. RED: (6 3) 13/4*
Another strong play from Mochy. The 4pt has MIP (most important point) status for both sides. If Red can make it he will effectively strangle White, if White can make it he will have good chances in a mutual holding game, particularly as he now holds the cube. 13/7, 9/6 is much too timid.
WHITE: (6 4) bar/21* 23/17

Brilliant. How many of us would have found this play instead of the "obvious" bar/21*/15? Why is it best, when it was correct to step out in the previous diagram? There the danger lay in Red hitting on and simultaneously making the 4pt. Here he can't do that, so White can leave it slotted as a point that he very much wants to make. Very easy to see now, but it also requires considerable courage to lay out 4 blots with the cube on 4! Note that fives and ones are duplicated and that the match play exerts a huge threat on Red's outfield blot. Well played.
16. RED: (6 3) Can't move
WHITE: (3 3) 24/21 17/14 13/10(2)
17. RED: (3 3) Can't move
WHITE: (6 2) 23/21 14/8

I don't see the point of this play. White doesn't have a cover number for the 8pt unless he gives up the more useful 10pt, so the blot is just a blot on the landscape. Moreover it creates a large gap between the 21pt and the 10pt. Keeping your checkers connected, i.e. within six pips of each other, was a feature that the old masters stressed constantly. It's less fashionable now in these more dynamic days, but still important here as White seeks to bring his back checkers out and round. 23/21/15 is the best play and the match play is an error.

18. RED: (4 4) bar/21 21/17*(2) 13/9
This is probably best, but bar/21, 21/17*(3) is almost equally good in the rollout. Making the 9pt is less valuable than usual as Red is now the pip leader again and doesn't need a blocking point that he will have to clear later. However it is a useful landing point. bbbbb
WHITE: (5 2) bar/23 7/2
19. RED: (6 3) 21/18*/12
WHITE: (6 1) bar/24 21/15
20. RED: (2 2) 12/10*/8 5/1*

I don't understand this play. If you are going to hit loose on the ace point you may as well make it. 12/10*/8, 3/1*(2) seems clear to me. The second best play in the rollout is 13/11, 12/10*/6 which demonstrates how damaging it is to be hit immediately. 13/11, 12/10*, 3/1*(2) doesn't do as well as any of these, presumably because getting a checker onto the 8pt is very important. Ibbbbbbbt has two functions there, being both a slot for the 8pt and an extra builder for the 2pt as required.
WHITE: (4 2) bar/21 bar/23
21. RED: (6 3) 17/8
WHITE: (3 2) 10/8* 5/2
22. RED: (6 2) Can't move
WHITE: (6 5) 21/15 10/5

When I first looked at this position I liked 21/10. Making the point 6 pips away from the "escape hatch"(here the 21pt) is usually very strong, guaranteeing that the checker on the bar can't enter and escape without leaving a shot. However the match play does best in the rollout, partly because it increases White's chances of picking up a second checker and partly perhaps, because it is slightly better connected. White might well want to make the 15pt for outfield control and as a staging post for the back men when they leave.
23. RED: (5 4) bar/16
Looks like a small error for mochy here. Bar/21, 13/8 leaves fewer shots and gets down to one blot.
WHITE: (2 1) 15/12*
24. RED: (4 2) bar/21 16/14
WHITE: (2 1) 12/11*/9
25. RED: (6 4) bar/15
WHITE: (6 5) 21/15 9/4*

Nobody liked this play at first sight and indeed snowie 3-ply marked it as a blunder. However a rollout shows that it is only a small mistake at worst. Hitting loose leaves 15 shots, whereas 21/10* only leaves 11, but note the better diversification after 21/15, 9/4*. If Red dances, White has sixes to escape, fives to hit a second checker, fours and ones to make a five point board and twos to get to the edge of Red's prime. After 21/10*, White has duplicated his own sixes and will often have to hit loose next turn anyway. So, interesting play, even if probably a small mistake.
Facile to point out how much White regrets not having played 23/21 with his two last turn.

26. RED: (5 2) Can't move
WHITE: (3 3) 15/6 4/1
White rolls a lemon; only 5-5 is worse. His play is good, probably equal to 15/6, 8/5 which concentrates on making the 4pt at the expense of duplicating his own twos

27. RED: (3 2) Can't move
WHITE: (6 2) 23/15
28. RED: (1 1) bar/24* 15/14 5/4*(2)

It's a great roll but how to play it? It's obvious that Red is going to put two men on the roof, but which two? Mochy though it right to play 5/4*(2) but giving up his 5pt is very damaging. A good sequence for White with the 20pt open might be a winner and it is pretty clear that Red needs to keep his five prime. Gnu 2-ply will play the same move as Mochy, but rollouts on Snowie and Gnu agree that this is a blunder. Bar/24*, 3/2*/1, 3/2 tops the rollout, with bar/24*, 15/14, 3/2*/1 a close second. Bar/24*, 15/14, 3/2*(2) is third and is a small error. This must be that if it comes to a blitz, as it often does, the 2pt or the 3pt are easier to cover than the 1pt. Note that plays including 15/14 expose Red to the superjoker 4-4 from the bar.
WHITE: (2 1) bar/23 bar/24*
29. RED: (5 1) bar/24 14/9
WHITE: (2 1) 6/4 5/4
30. RED: (6 4) 24/14
WHITE: (5 3) 23/15
31. RED: (6 5) 24/18 14/9
WHITE: (3 3) 23/20 15/12(2) 8/5
32. RED: (6 5) 18/7
WHITE: (3 1) 24/20
33. RED: (3 1) 9/6 9/8
WHITE: (2 2) 12/8 5/1
I can't see the point of slotting the ace point; 12/6, 12/10 looks better, but it doesn't matter much.
34. RED: (4 3) 8/1
WHITE: (6 3) 12/3
35. RED: (5 2) 7/2 3/1
WHITE: (2 1) 8/7 3/1
36. RED: (4 2) 8/4 8/6
WHITE: (5 2) 20/13

Martin correctly runs while Red has two blots inboard. He still trails by 7 after the roll, but he isn't going to get a shot next turn so trashing the board and hoping to win after a shot in two or three turns time isn't realistic. Staying back also wastes pips in a close race. Good play.
37. RED: (5 4) 7/2 7/3
WHITE: (3 3) 20/11 13/10
38. RED: (6 6) 9/3(2) 6/off(2)
WHITE: (2 2) 11/9 10/6 7/5
39. RED: (2 1) 2/off 1/off
WHITE: (4 2) 9/5 2/off
40. RED: (6 4) 6/off 4/off
WHITE: (6 1) 6/off 1/off
41. RED: (6 5) 6/off 4/off
WHITE: (3 1) 3/off 1/off
42. RED: (3 2) 3/off 2/off
WHITE: (6 3) 6/off 3/off
43. RED: (6 1) 4/off 1/off
WHITE: (5 3) 6/3 5/off
44. RED: (3 2) 3/off 3/1
WHITE: (3 2) 3/off 2/off
45. RED: (4 1) 3/off 1/off

And Mochy wins 4 points to lead 4-1 going into the third game. We'll add that one next week.
Looking at some of these positions and waiting for rollouts can be time consuming so be patient. I do hope that you are enjoying it and learning from it. You'll get the most benefit if you play the rolls out on a board, rather than just looking at the diagrams. Until next week, enjoy the game!

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