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A pawn endgame analysis

Posted: Sun Jul 28, 2019 6:19 pm
by Look
Hi,

Following an online game, this pawn endgame happened :



How do you analyse it ?

Also a line led to the following position for me :



What is your tell ?

Re: A pawn endgame analysis

Posted: Sun Jul 28, 2019 7:14 pm
by zullil
Look wrote:
Sun Jul 28, 2019 6:19 pm



What is your tell ?
This is a draw. Check here, for example: https://www.shredderchess.com/online-ch ... abase.html

Or here: https://syzygy-tables.info/?fen=6Q1/8/8 ... _b_-_-_0_1

The original position appears to be a draw as well:

0.00 27. Kf4 Ke6 28. Kg5 Kd5 29. Kh6 c5 30. h4 cxd4 31. cxd4 Kxd4 32. Kxh7 e5 33. Kxg6 e4 34. h5 e3 35. h6 e2 36. h7 Kd3 37. h8=Q e1=Q 38. Qh3+ Kc2 39. Qb3+ Kc1 40. Qc4+ Kb2 41. g4 a5 42. a4 Qb4 43. Qb5 Ka3 44. g5 Qe4+ 45. Kf6 Qf4+ 46. Ke6 Qe4+ 47. Kd6 Qd4+ 48. Qd5 Qb6+ 49. Kd7 Qa7+ 50. Ke6 Qe3+ 51. Kf7 Qf4+ 52. Kg8 Qb8+ 53. Kf7 (depth 74, 0:08:16)

Re: A pawn endgame analysis

Posted: Sun Jul 28, 2019 7:46 pm
by Ovyron
Yeah, also, if you're on mobile you can download a "7men Lomonosov Tablebases" application (that uses my curved arrows for Knight moves :mrgreen: ) where you can input any position with 7 pieces or less and it tells you if it's drawn or not, and how many moves to mate. If you only care about game result and not the moves you can also paste a position with 7 pieces or less into lichess's Analysis board and it will tell you.

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 3:41 pm
by Look
Ovyron wrote:
Sun Jul 28, 2019 7:46 pm
Yeah, also, if you're on mobile you can download a "7men Lomonosov Tablebases" application (that uses my curved arrows for Knight moves :mrgreen: ) where you can input any position with 7 pieces or less and it tells you if it's drawn or not, and how many moves to mate. If you only care about game result and not the moves you can also paste a position with 7 pieces or less into lichess's Analysis board and it will tell you.
I care about moves in EGTB. For instance consider some KRB vs kr which is equal in some positions. But it is difficult to achieve draw as mistakes may lead to loss for weaker side.

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 3:45 pm
by Look
[...]
zullil wrote:
Sun Jul 28, 2019 7:14 pm

The original position appears to be a draw as well:

0.00 27. Kf4 Ke6 28. Kg5 Kd5 29. Kh6 c5 30. h4 cxd4 31. cxd4 Kxd4 32. Kxh7 e5 33. Kxg6 e4 34. h5 e3 35. h6 e2 36. h7 Kd3 37. h8=Q e1=Q 38. Qh3+ Kc2 39. Qb3+ Kc1 40. Qc4+ Kb2 41. g4 a5 42. a4 Qb4 43. Qb5 Ka3 44. g5 Qe4+ 45. Kf6 Qf4+ 46. Ke6 Qe4+ 47. Kd6 Qd4+ 48. Qd5 Qb6+ 49. Kd7 Qa7+ 50. Ke6 Qe3+ 51. Kf7 Qf4+ 52. Kg8 Qb8+ 53. Kf7 (depth 74, 0:08:16)
What is your engine ?
BTW what happenes after 27. Ke4

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 5:04 pm
by zullil
Look wrote:
Mon Jul 29, 2019 3:45 pm
[...]
zullil wrote:
Sun Jul 28, 2019 7:14 pm

The original position appears to be a draw as well:

0.00 27. Kf4 Ke6 28. Kg5 Kd5 29. Kh6 c5 30. h4 cxd4 31. cxd4 Kxd4 32. Kxh7 e5 33. Kxg6 e4 34. h5 e3 35. h6 e2 36. h7 Kd3 37. h8=Q e1=Q 38. Qh3+ Kc2 39. Qb3+ Kc1 40. Qc4+ Kb2 41. g4 a5 42. a4 Qb4 43. Qb5 Ka3 44. g5 Qe4+ 45. Kf6 Qf4+ 46. Ke6 Qe4+ 47. Kd6 Qd4+ 48. Qd5 Qb6+ 49. Kd7 Qa7+ 50. Ke6 Qe3+ 51. Kf7 Qf4+ 52. Kg8 Qb8+ 53. Kf7 (depth 74, 0:08:16)
What is your engine ?
BTW what happenes after 27. Ke4
Cfish-dev with 6-man tables, 20 threads, 64 GB hash table.

After 27. Ke4:

0.00 27... Ke6 28. h4 Kd6 29. g3 c5 30. d5 a5 31. c4 a4 32. Kf4 h6 33. g4 e6 34. dxe6 Kxe6 35. h5 g5+ 36. Ke4 a3 37. Kd3 Kf6 38. Ke2 Ke5 39. Ke3 Kf6 40. Kd3 Kf7 41. Ke2 Kg7 (depth 88, 0:56:13)

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 5:31 pm
by Ovyron
Look wrote:
Mon Jul 29, 2019 3:41 pm
I care about moves in EGTB. For instance consider some KRB vs kr which is equal in some positions. But it is difficult to achieve draw as mistakes may lead to loss for weaker side.
The place zullil linked to is best for this with 6 pieces or less:

https://www.shredderchess.com/online-ch ... abase.html

Just put pieces on the board and it'll tell you.

For 7 pieces the options I already listed should work.

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 6:54 pm
by Vinvin
Ovyron wrote:
Mon Jul 29, 2019 5:31 pm
Look wrote:
Mon Jul 29, 2019 3:41 pm
I care about moves in EGTB. For instance consider some KRB vs kr which is equal in some positions. But it is difficult to achieve draw as mistakes may lead to loss for weaker side.
The place zullil linked to is best for this with 6 pieces or less:

https://www.shredderchess.com/online-ch ... abase.html

Just put pieces on the board and it'll tell you.

For 7 pieces the options I already listed should work.
I think Lichess is way better : https://lichess.org/analysis
Click on the book icon and you will see the distance to conversion, even with 7 pieces.
If you don't have the FEN, you can enter the position here https://lichess.org/editor, then click "Analyzing board".

Re: A pawn endgame analysis

Posted: Mon Jul 29, 2019 9:47 pm
by Ovyron
Vinvin wrote:
Mon Jul 29, 2019 6:54 pm
Click on the book icon and you will see the distance to conversion
Really? You call that better??

Check this position out:



What does the 7men Lomonosov app say?

Image

Oh, okay, so Bf4!! and Kf5!! are best, because they mate in 18 and other moves waste time.

What does lichess say?

Image

"Derp! Be3+ has best distance to conversion! After it capturing the Bishop is white's worst move! Let's give the Bishop up for no reason at all!"

:shock:

Why would someone recommend a site that suggests moves as bad as Leela's on the endgame, that doesn't know how many moves to mate. It's beyond me.

Distance to conversion sucks.

Re: A pawn endgame analysis

Posted: Tue Jul 30, 2019 9:01 am
by zullil
Ovyron wrote:
Mon Jul 29, 2019 9:47 pm

Distance to conversion sucks.
Well, it has at least one good feature. :wink:

Code: Select all

7	423,836,835,667,331	Syzygy		 17 TB
7	423,836,835,667,331	Lomonosov	140 TB
https://en.wikipedia.org/wiki/Endgame_tablebase