World Draughts Forum

In this subject I propose to try and find what is the result of the following famous position that we saw regularly and the top level. This position appear in particular in 1967 between T.Sijbrands and M.Hisard, and this position appeared of course during this last world chamionship in the Otgonbayar-Podolski game.


White to play

As far as I know nobody could demonstrate what the issue is.
My view (correct me if I am wrong) is that the best defense for white is
1.34-29 23x34 2.30x39 18-23 3.39-34 12-18 4.35-30 24x35 5.27-22 18x27 6.33-29 13-18 7.29-24 19x39 8.28x10
and we are in the following position


Black to play

It seems to me that this is the key position to resolve the initial problem.
The analysis of this position is very difficult but I am sure that with the collaboration of srtong analysts we should finaly find the solution of the problem.

My proposition is to play here 8...35-40

After some discussion with Wieger Wesselink it appears that after
8...35-40 9.25-20 40-44! 3.20-15 18-22! black as very good chances of winning
We did not discuss the following gambit, proposed by T.Sijbrands
8...35-40 9.10-04 18-22 10.38-33 27x29 11.04x31/36 but it seems to me that here again black has very good perpectives.

Who is interesting by such a discussion ?

<img src="http://fmjd.org/dias2/save/11808165564.png">

In this position, white has two defenses: 7.28-22 and 7.29-24. To proof a win for black, we need to find replies to both moves.

Sijbrands states he's not sure that black will win after 7.28-22 35-40 8.22x24 40-44 9.29x18 44-49 10.24-20 14-19 11.18-12

<img src="http://fmjd.org/dias2/save/11808169818.png">

but after the logical 11. ... 21-26 12.32x21 26x8

<img src="http://fmjd.org/dias2/save/11808174242.png">

white has to decide between (note that 13.38-33 19-24!! 14.20x29 49-44! and black wins):
1) 13.20-15 49x41/46 with a difficult 5 vs 3 endgame with a vulnerable white piece on 34
2) 13.37-32 19-23 14.34-30! 23-29 (the exchange with 23-28 into a 4 vs 2 endgame is a draw according to Flits' endgame database) 15.20-15 49-35 16.32-27 35x31/36 with another difficult 5 vs 3 endgame with a vulnerable white piece on 38

Both 5 vs 3 endgames should be forceable into 5 vs 2 rather quickly because of the loose white pieces, so perhaps someone with access to the 7-piece endgame databases could resolve these endgames?



Wieger continues here with 11.10-4 44-50! 12.38-33 27x29 13.4x36 29-33!! (14.25-20? 21-27 B+) 14.37-32 39-43! 15.15-10 33-39!! and a promising 6 vs 3 endgame for black.

For completeness, you proposed 10.20-14 18-22! White can then move either (note that after 11.10-4? black wins with 22-28! 44-50 and 21-27)
1) 11.10-5 44-49 and after
1.1) 12.14-10 39-44 13.10-4 21-26!! and black wins)
1.2) 12. 5-10 39-44 13.38-33 27x29 14.10-15 29-34 15.14-10 44-50 and white can't promote his second piece.
2) 11.14-9 44-49 12.38-33 27x29 with another hopeless 7 vs 3 endgame.

So I would agree with you and Wieger that after 9.25-20 etc. black can almost surely win.



Given the above bleak results for white, I would say that white should play Sijbrands' 9.10-4 instead of Wieger's 9.25-20. Sijbrands states that after 9.10-4 18-22 white's strongest move is to play 10.38-33?, which however leads to a 6 vs 3 endgame which seems quite bad for white indeed.

But with 10.4-15! 40-44 (Sijbrands concludes that white can hardly escape a loss here and doesn't analyse further) 11.15-29 44-49 12.29-45 11-17 13.38-33 27x29 14.45x31/36 white has a 5 vs 3 endgame, however with a vulnerable piece on 37 and his other piece on 25 quite a way from promotion. Can black win this by exchanging into a 5 vs 2?

1.34-29 23x34 2.30x39 18-23 3.39-34 12-18 4.35-30 24x35 5.27-22 18x27 6.33-29 13-18

Summarizing the positions which are not quite clear yet (other variations lose more material or win by your/Wieger's method)

1) 7.28-22 35-40 8.22x24 40-44 9.29x18 44-49 10.24-20 14-19 11.18-12 21-26 12.32x21 26x8

1.1) 13.20-15 49x46 (or x41)
<img src="http://fmjd.org/dias2/save/11808226564.png">
(black king also on 41) White to play.

1.2) 13.37-32 19-23 14.34-30! 23-29 15.20-15 49-35 16.32-27 35x36 (or x31)
<img src="http://fmjd.org/dias2/save/11808224855.png">
(black king also on 31) White to play.

2) 7.29-24 19x39 8.28x10 35-30 9.10-04 18-22 10.4-15! 40-44 11.15-29 44-49 12.29-45 11-17 13.38-33 27x29 14.45x36 (or x31)
<img src="http://fmjd.org/dias2/save/11808235697.png">
(white king also on 31) Black to play.

After 10.4-15! 40-44 11.15-29

I propose to follow with 11...44-50 with the idea 12.29-45 21-26 13.32x21 16x27 14.25-20 39-44 15.45-29 44-49 16.38-32 27x38 17.29x47/42 22-28 with the intention 49-32

I propose to continue here by 14.15-10 11-17 15.10-04 19-24 16.04-31 (to avoid 34-30) 46-10 and the situation becomes very difficult for white

6 should be on 11 here, right? Then 18.20-14 49-32 19.47-20 (19.14-9?? 32x41!!) 32x41 with a 5 vs 2 endgame.
<img src="http://fmjd.org/dias2/save/11808626454.png">
White to play. Do you have access to a 5 vs 2 database?

Is there a problem with the simple continuation 17.15-10 29-34 18.10-05 36-47 19.38-32 34-40 etc.

yes of course.
Corrected diagram :

<img src="http://fmjd.org/dias2/save/11808634686.png">
Yes, if black can play 24-30 it becomes rather hopeless for white but after
17.31-4 10-5 18.4-9 16-21 19.9-18 21-26 20.18-1 5-28 21.1-18 28-10 22.18-7 10-32 23.7-1
<img src="http://fmjd.org/dias2/save/11808635551.png">
Black to play. How is black ever going to play 24-30?

Ik denk, dat de discussie hier de verkeerde kant uitgaat. De essentiele vraag is of wit een tweede dam kan halen. Als hem dit lukt dan is het remise. Zelfs als zwart een relatief groot aantal stukken aan de verkeerde kant van de lange lijn houdt. Het bezwaar van 35-40 is, dat niets wit weerhoudt onmiddelijk aan de tweede dam te werken met 25-20. In de stampartij was dat na (39-44) 25-20 (22-28) X niet mogelijk. Het ligt daarbij voor de hand de opmars van schijf 25 te beginnen zelfs nog voor er damgehaald wordt met de voorste schijf. Zinloos schuiven met de enige witte dam leidt tot niets.

(I think the discussion goes the wrong direction. The important question is if it is possible for white to get a second king. If this is possible, then the position is draw. Even when black keeps enough pieces on the wrong site of the long diagional. The main problem of 35-40 is the possibility to work on the second king immidiately with 25-20. It make since to start with the action even before taking a king with the piec on 10. Meainingless moving of the only one king doesn't do nothing)

Do we need the 5 vs 2 database ? How can you avoid that black makes 5 kings ?

See Wieger's post for the variation 9.25-20 40-44 10.20-15 18-22! 11.10-4 44-50! 12.38-33 27x29 13.4x36 29-33!! (14.25-20? 21-27 B+) 14.37-32 39-43! 15.15-10 33-39!!

Because this position is rather depressing for white, I started looking for alternatives like 9.10-4.

By the way, can you substantiate your claim that it is a draw when white gets two kings? Even 5 vs 3 with 2 white kings seems very difficult to defend for white.

1.34-29 23x34 2.30x39 18-23 3.39-34 12-18 4.35-30 24x35 5.27-22 18x27 6.33-29 13-18

Summarizing the positions which are not quite clear yet (with updates of the analysis so far)

1) 7.28-22 35-40 8.22x24 40-44 9.29x18 44-49 10.24-20 14-19 11.18-12 21-26 12.32x21 26x8

1.1) 13.20-15 49x46 (or x41) 14.15-10 11-17 15.10-04 19-24 16.04-31 (to avoid 34-30) 46-10 17.31-4 10-5 18.4-9 16-21 19.9-18 21-26 20.18-1 5-28 21.1-18 28-10 22.18-7 10-32 23.7-1
[img]http://fmjd.org/dias2/save/11808635551.png[/img]
Black to play. Can black ever continue with 24-30?

1.2) 13.37-32 19-23 14.34-30! 23-29 15.20-15 49-35 16.32-27 35x36 17.15-10 29-34 18.10-05 36-47 19.38-32 34-40
[img]http://fmjd.org/dias2/save/11808724092.png[/img]
White to play. Can white avoid the imminent defeat?

2) 7.29-24 19x39 8.28x10 35-30 9.10-04 18-22 10.4-15! 40-44 11.15-29 44-50 with the idea 12.29-45 21-26 13.32x21 16x27 14.25-20 39-44 15.45-29 44-49 16.38-32 27x38 17.29x47/42 22-28 18.20-14 49-32 19.47-20 (19.14-9?? 32x41!!) 32x41
[img]http://fmjd.org/dias2/save/11808626454.png[/img]
White to play. Can white stop black from getting 5 kings?

I would say that variation 1.1) with 7.28-22 and 13.20-15 gives the best defense for white. If black can win that position, white is probably lost.

When you ask Truus voor comments about the possition. She give in most variations the run 25-20-14 as best solution before deciding about the spot where the first king have to be made. The possibility to take king on field 5 makes a king for black on field 49 not always the most likely possibility. Truus and I are the ideal combination for playing this kind of positions. It is so a pity, that it isn't allowed during normal games. I don't see any combination and see haven't any idear what the important moves are.

My idea with 16...46-10 was not to stay on the long diagonal but rather to take the 04-36 diagonal with a development like :
17...10-15 18.04-18 15-04 19.18-07 17-21 20.07-02 04-13 21.02-07 21-27 22.07-23 and now it seems to me that black can force the white king to leave the long diagonal by 22...13-04 23.23-28 08-13 24.28-37 13-18 25.37-26 (25.37-41 18-22 26.41-37 04-18 ) 27-32 26.26-08 04-15 27.08x35 32-37 with very good perspectives to make 4 kings and win