| Jan-25-22 | | Brenin: 46 Bxg6, e.g. 46 ... Bxg6 47 Rxg6+ Kxe7 (Kxg6 48 e8=Q+) 48 Rg7+ Kd8 49 h4 with an easy win, or 46 ... Bxg3 47 hxg3 B(or K)xg6 48 c7 and the c- or e-pawn promotes, or 46 ... Kxe7 47 Re3+ winning a piece. |
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| Jan-25-22 | | TheaN: Ah I'm sloppy on a Tuesday. <46.Bxg6! Bxg3> 46....Bxg6 fails rather obviously on 47.Rxg6+! Kxe7 (else e8Q) 48.Rg7+ Kd8 and here even 49.Rxc7!? wins, as Black runs out of tempos in the pawn endgame. However, now I played <47.Bxe8?!>. 47.hxg3 is much more logical, as the c-pawn's only defender is gone. In this line, after <47....Bxh2 48.Bxh5 Kxe7 49.Kc5>:
click for larger view
White's going to pick up b5, but it's probably not enough after <49....Bd6+!> blocking off the king afterwards <50.Kxb5 Kd8=> unless I miss something this is a draw. Sadly this is one piece too many for the 7-men table base. The 51.Ka6 line is fruitless: 51....Kc7 52.Kxa7? Kxc6= is a definite draw: https://syzygy-tables.info/?fen=8/K... because the pawns can't move. White would want to keep his a- and b-pawn supported, but then Black can get the a5-d8 phalanx rather easily. 51.a4, for example, 51....Kc7 and White needs to defend Pc6 because of a6+, otherwise either b4 or c6 fall. 52.Bf3 a6+! 53.Kc4 (Kxa6 Bxb4=, Ka5 Be7=) Bf8= and White has no way to make progress. Tl;dr, 47.hxg3 1-0. |
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| Jan-25-22 | | yrotciv: I prefer: 46. Rxg6+ Kxf5 47. Rg8 Bg6 48. e8=Q Bxe8 49. Rxe8 Kg4 50. Re7 Bb6 51. c7 Since the check is more forcing and the rook can chase away both bishops later |
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| Jan-25-22 | | yrotciv: Or 46. Rxg6+ Kxf5 47. Rg8 Kf6 48. Rxe8 Kf7 49. Rc8 Kxe7 50. Rxc7+ |
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| Jan-25-22 | | mel gibson: I saw the first ply straight away but as Stockfish 14 shows there are many lines.
It's mate in 17:
46. Bxg6
(46. Bxg6 (♗f5xg6 h5-h4 ♖g3-g4 ♔f6xe7 ♗g6xe8
♔e7-f6 ♖g4xh4 ♔f6-g7 ♖h4-g4+ ♔g7-f6 ♖g4-g6+ ♔f6-e7 ♖g6-g7+ ♔e7-d8 ♖g7xc7
♔d8xc7 ♗e8-f7 a7-a5 ♗f7-h5 a5-a4 ♔d5-c5 ♔c7-b8 ♔c5-d6 ♔b8-c8 c6-c7 ♔c8-b7
♗h5-g4 ♔b7-b6 c7-c8♕ ♔b6-a7 ♕c8-c7+ ♔a7-a8 ♗g4-f3+) +M17/59 361) White wins - mate in 17. |
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| Jan-25-22 | | yrotciv: ANALYSIS[x]46. Rxg6+ Bxg6 47. Bxg6 Kxe7 48. h4 Bg3 49. Bxh5 Kd8 50. Bg6 Bxh4 51. Kc5 a6 52. Kb6 Bf2+ 53. Kxa6 Kc7 54. Be4 Bd4 55. Kxb5 Bb2 56. a4 Bd4 57. Kc4 Ba7 58. a5 Bg1 59. b5 Ba7 60. b6+ Bxb6 61. axb6+ Kxb6 62. Kd5 Kc7 63. Ke6 Kc8 64. Ke7 Kc7 65. Ke6 Kc8 66. Kd6 Kd8 67. Bf5 Ke8 68. c7
Or 46. Rxg6+ Bxg6 47. Bxg6 Kxe7 48. h4 Bg3 49. Bxh5 Kd8 50. Bg6 Kc7 51. h5 |
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| Jan-25-22 | | yrotciv: 46. Rxg6+ Bxg6 47. Bxg6 Kxe7 48. h4 Bg3 49. Kc5 a6 50. Kb6 or
49. Bxh5 Kd8 50. Kc5 Kc7 51. Kxb5 are all good for white |
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| Jan-25-22 | | Refused: 1.Bxg6 and black can't stop both pawns.
a)1...Bxg6 2.Rxg6+ Kxe7 3.Rg7+ Ke8 is presumably relatively best for black. White can either sac the exchange to go for a won pawn ending, or just play (p)h3-Rh7 and collect another pawn. I mean why not? b)1...Kxe7 2.Re3+ nets a full piece.
c) 1...Rxg3 2.hxg3 Bxg6 3.c7+-
c1) 2...Kxe7 3.Bxe8 Kxe8 4.Kd6 Kd8 5.c7+ Kc8 now pretty much any reasonable move mates rather quick sample line 6.h4 a6 7.Kc6 a5 8.bxa5 b4 9.a6 b3 10.a7 b2 11.a8R# |
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| Jan-25-22 | | agb2002: White has a rook and a pawn for a bishop.
Black threatens gxf5 and Bxg3.
The bishop on e8 controls both promotion squares. This suggests 46.Bxg6: A) 46... Bxg3 47.hxg3
A.1) 47... Kxg6 48.c7 Bd7 49.c8=Q Bxc8 50.e8=Q+ wins. A.2) 47... Bxg6 48.c7 wins (48... Bf5 49.e8=Q).
A.3) 47... Kxe7 48.Bxe8 Kxe8 49.Kc5 a6 50.Kb6 wins the pawn ending. B) 46... Bxg6 47.Rxg6+ Kxe7 (47... Kxg6 48.e8=Q+ wins) 48.Rg7+ Kd8 49.Rxc7 Kxc7 50.Kc5 a6 51.h4, followed by 52.Kb6, wins the ending. C) 46... Kxe7 47.Re3+ wins a bishop.
D) 46... h4 47.Rg4 just delays one move the defeat. |
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| Jan-25-22 | | saturn2: 46.Bd3 avoids complications and wins easily. |
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| Jan-25-22 | | raymondhow: I did choose the game line, but sure didn't seem easy. |
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| Jan-25-22 | | Aware: Definitely a Wednesday level puzzle. |
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Jan-25-22
 | | Teyss: Yes other moves also win including retreating the B and Rxg6+ which delivers a small advantage but the <best move> as expected in a POTD is Bxg6. Underpromotion on Monday, four main lines on Tuesday... it's going to be a long week. |
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| Jan-25-22 | | Stanco: Bxg6 is neat and clean |
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| Jan-25-22 | | parch: 46.B:g6 K:e7
(46...B:g3 47.hg3 B:c6+ 48.K:c6 K:e7 48.B:h5 )
47.B:e8 K:e8 48.Rg7 B:h2 49.c7 B:c7 50.Ke6 |
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Jan-25-22
 | | chrisowen: Rutz v it ie vans o Bxg6 hobble it i v achtung munch blubb c it i vic bow it rutz v it ie vans o joffrey hod joshed it i v bugs gaps camp it will flint foot ruz it i v kev it i v ye q it i v foal josh dang be pick i x i v tums it i way u z v it prawns ah it rad griffon it i v pg it i v fits i v flush gg it ice v it i flock fetch accomodate mack ghost conc hood duress cress it i v c find o it if da hals sans prods it i v cogs ammy labs it i v cells v it i ment pt it rent v it rest clap hads plys c hams ammo c it wag it i v it i v nax tin c hind roof u v it i v prop goo v it rid hons it v im pa vert it wins harly romp sh i suns cc ie ogle ah forfeit i vets dads leds it i v clot ko it v i hilly dr tows fabs v it way toddy fc hox it i v pecs c hogs deaf hogs hoof adept accomplish cate v it wary v it dog hots nt it ron la z o c bull nt band it wagon ques tn ents it wang look bubble by bluff it i v zilch dr fuel it v i blat sh it rats on fed it rum tons eh au boot lit i v earn cane it i v co i run cuts it v ok it i v papa care it i v blotch dont phhi caps v it i num pr he bams moms it i v mc batch o hilt im it what o v it i v sun slims lay tod dea wit brec fabbled it i v bode it roof buck con ah c nads fame it i v lags hids mc dope it i v toad fare it i v u cdts fore it i v coms rade it as add mc v it v lads made it fang it a v hics c bed it ref c it eddy odds ft dank budge it do foot gab it v i doff it tar it pour it ram op mar its alan a v it cam saint et pocket abort it re dew it i v aut ar it row it i v lasa mans came it i v bots a mop it ra v it i v line it weed it ran a o v it i bods u taos om pa la ma cans abode it i v awe it i Bxg6 cite? |
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| Jan-25-22 | | Refused: < TheaN: Ah I'm sloppy on a Tuesday. <46.Bxg6! Bxg3> 46....Bxg6 fails rather obviously on 47.Rxg6+! Kxe7 (else e8Q) 48.Rg7+ Kd8 and here even 49.Rxc7!? wins, as Black runs out of tempos in the pawn endgame.
However, now I played <47.Bxe8?!>. 47.hxg3 is much more logical, as the c-pawn's only defender is gone. In this line, after <47....Bxh2 48.Bxh5 Kxe7 49.Kc5>: click for larger view
White's going to pick up b5, but it's probably not enough after <49....Bd6+!> blocking off the king afterwards <50.Kxb5 Kd8=> unless I miss something this is a draw. Sadly this is one piece too many for the 7-men table base. The 51.Ka6 line is fruitless: 51....Kc7 52.Kxa7? Kxc6= is a definite draw: https://syzygy-tables.info/?fen=8/K... because the pawns can't move. White would want to keep his a- and b-pawn supported, but then Black can get the a5-d8 phalanx rather easily. 51.a4, for example, 51....Kc7 and White needs to defend Pc6 because of a6+, otherwise either b4 or c6 fall. 52.Bf3 a6+! 53.Kc4 (Kxa6 Bxb4=, Ka5 Be7=) Bf8= and White has no way to make progress. Tl;dr, 47.hxg3 1-0.>
More stylistic thing, rather than criticism.
I'd go 49...Bg1+ and claim you are never ever gonna make any proress. 50.Kxb5 Kd6 51.any move Kc7
And now I will keep on moving the bishop on the g1-a7 diagonal for posterity. Just feels a bit more natural to me to establish a dark squared blockade this way. |
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| Jan-25-22 | | TheaN: <Refused: More stylistic thing, rather than criticism. I'd go 49...Bg1+ and claim you are never ever gonna make any progress.> And you're right to do so, that's probably the best visual explanation why opposite bishops give rise to such weird endgames: 49....Bg1+ 50.Kxb5 Kd6 51.Bf3 Kc7:
click for larger view
And because Black perpetually (unless he moves the king or bishop elsewhere which serves no point) controls b6 twice White gets nowhere, easier than in the 'computer' line (exhaustive computers don't get these kind of positions as technically White's winning, they just repeat the position for 50 moves). Illustrative is Black pre-moving Bf2-Bg1: 52.a4 Bf2 53.a5 Bg1 54.Ka4 Bf2 55.b5 Bg1:
click for larger view
And the only move White can do to make progress is 56.b6: 56....axb6 57.a6 (axb6 Bxb6 1/2) b5+ 58.Kxb5 1/2 as White can never go around. Mind if White decides to put the king on a6, b6 forces trade of pawns and a dead draw as well. |
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| Jan-25-22 | | TheaN: <yrotciv: 46. Rxg6+ Bxg6 47. Bxg6 Kxe7 48. h4 Bg3 49. Kc5 a6 50. Kb6 or 49. Bxh5 Kd8 50. Kc5 Kc7 51. Kxb5 are all good for white> <Teyss: Yes other moves also win including retreating the B and Rxg6+...> Rxg6+ does <not> win because it leads to the exact same opposite bishop ending I ended in (see the other posts). I know for Teyss it was mentioned as matter of principle :> To <yrotciv>: why 49....a6? One thing you're <never> supposed to do in an opposite bishop ending is needlessly shift pawns to the opposing bishop's color. You both allow the king in and put it on a light square. After 49....Bxh4 followed by Bf2 it's a draw. Don't let the +1 computer evaluation confuse you. |
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Jan-25-22
 | | gawain: I was very slow to see what a problem White's c6 pawn poses for Black in some variations. |
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Jan-26-22
| | Teyss: <TheaN> You are right about both Rxg6+ and the principle, thanks for the correction. I first thought Rxg6+ was winning but too slowly for a Tuesday so looked at Bxg6 and didn't reassess the other option. Reading your excellent (as usual) posts it now makes complete sense. Cheers. |
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Kibitzing
sac: 46.Bxg6
