|Aug-08-19|| ||kungfufighter888: Black play Rook b1 check win ?|
|Aug-08-19|| ||Cheapo by the Dozen: White has a winning material advantage, but if he can't force simplification, Black has outastanding chances for a perpetual check. 38 Rxg7+ sacrifices a rook (for a pawn), in the confident expectation that White will shortly be able to win Black's queen for the other rook, or else mate.|
In the actual game Black chose a line that led to getting mated.
|Aug-08-19|| ||Cheapo by the Dozen: <kungfufighter888>: Did you overlook the fact that Black is in check?|
|Aug-08-19|| ||goldfarbdj: kungfufighter888 might have been talking about the initial puzzle position, where Black can't play Rb1+ because it isn't Black's turn.|
Of course, in both cases Qd1 seems to me a much stronger move if it were legal. (38 ... Qd1+ 39 Qe1 Qxf3+ and mate next.)
As for me: given Black's massive threats against White's exposed king, it was obvious that something very forcing was required. Rxg7+ was the obvious choice, and it was just a matter of verifying that 38 ... Kxg7 39. Qg5+ was winning. I worked out the game line, and also 40...Ke6 41. Rh6+ Kd7 42. Rxd6+ Kxd6 43. Qf6+, picking up the rook on b2.
|Aug-08-19|| ||newzild: Black's best defence is probably:
38. Rxg7+ Kxg7
39. Qg5+ Qg6
40. Qe7+ Kg8 (not 40...Qf7 Rh7+, when White will also pick up the Rb2)
And now after 41. Rg5 Rb1+, it will be rook vs queen.
|Aug-08-19|| ||Cheapo by the Dozen: Or perhaps the question was why Black didn't play 37 ... Rxb1+, which was less bad than the game move in that it delayed White getting the initiative.|
|Aug-08-19|| ||Manu2: I really wonder why Black was so greed instead of simply going for 37....Rb1+. It has very good chances if not winning actually|
|Aug-08-19|| ||patzer2: Today's Thursday puzzle solution 38. Rxg7+ +- features an instructive King hunt using the heavy artillery (i.e. Rooks and Queen versus Rooks and Queens).|
So where did Black go wrong? The decisive error was 34...e4? allowing 35. Rdh5 +- (+4.57 @ 29 ply, Stockfish 10) or 35. d7 +- (+10.09 @ 30 ply, Stockfish 10).
Instead, Black could have held the game level with 34...Rxe2 35. Kxe2 Qg2+ 36. Qf2 Qxh1 = (0.00 @ 35 ply, Stockfish 10).
|Aug-08-19|| ||Lambda: 38...Kf8 must also be considered. White's goal is generally to chase the black king to somewhere Qg5 can be played with check.|
|Aug-08-19|| ||latebishop: 37...Rb1+ looks saving but after 38.Ke2 Qxg1 (38...Rxg1 39.Qb3+ Kf8 40. Rh8 mate) 39.Qxg1 Rxg1 40.d7 exf3+ 41.Kd2 f2 42.d8=Q+ Kf7 43.Qd7+ White mates.|
38...Q×f3+ also doesn't seem to work.
|Aug-08-19|| ||saturn2: I saw 38. Rxg7+ Kxg7 39. Qg5+
Kf7 (or..Qg6 40. Qe7+ Qf7 41. Rg5+) Rh7+ Ke8 41. Qg8+ Qf8 42. Qe6+
|Aug-08-19|| ||agb2002: White has a rook for two pawns.
Black threatens Qd1+ and mate in two.
The first idea that comes to mind is 38.Rxg7+:
A) 38... Kxg7 39.Qg1+
A.1) 39... Qg6 40.Qd4+ (40.Rg5 Rb1+ wins for Black)
A.1.a) 40... Qf6 41.Rh7+ Kg6 42.Rh6+ wins.
A.1.b) 40... Kf7 41.Qd5+
A.1.b.i) 41... Kf6 42.Qe5+ Kf7 43.Rf5+ Kg8 44.Rg5 wins decisive material.
A.1.b.ii) 41... Kg7 42.Rg5 as above.
A.1.b.iii) 41... Ke8 42.Rh8+ Ke7 43.Qe5+ followed by 44.Qxb2 wins decisive material.
A.1.b.iv) 41... Ke7 42.Re5+ Kf8 (42.... Kf6 43.Re6+ wins decisive material) 43.Qd8+ Kf7 (43... Kg7 44.Rg5) 44.Qe7+ Kg8 45.Rg5 wins decisive material.
A.1.b.v) 41... Qe6 42.Rh7+ wins.
A.1.c) 40... Kg(f)8 41.Rh8+ followed by 42.Qxb2 wins decisive material.
A.2) 39... Kf8 40.Rh8+ Ke7 (40... Kf7 41.Qg8+ Ke7 -41... Kf6 42.Rh6+ wins- 42.Qg7+ as in the line) 41.Qg7+ Ke6 42.Rh6+ wins.
A.3) 39... Kf7 40.Rh7+
A.3.a) 40... Kf(e)6 41.Rh6+ wins decisive material (41... Ke5(7) 42.Qg5+, etc.).
A.3.b) 40... Ke8 41.Qg8+ Qf8 42.Qe6+ and mate next.
A.3.c) 40... Kf8 41.Qg7+ Ke8 42.Rh8+ Qf8 43.Rxf8#.
A.4) 39... Kf6 40.Rh6+ wins.
B) 38... Kf8 39.Rf5+
B.1) 39... Ke8 40.Qxe4+ with a winning attack.
B.2) 39... Kxg7 40.Qg5+
B.2.a) 40... Qg6 41.Qe7+ Kh6 (41... Kg8 42.Rf8#; 41... Kh8 42.Rg8+ and mate in two) 42.Rf6 wins decisive material.
B.2.b) 40... Kh7 41.Rf7+ Kh8 42.Qg7#.
B.2.c) 40... Kh8 41.Qh5+ Kg8 (41... Kg7 42.Rf7+ Kg8 43.Qh7#) 42.Qf7+ Kh8 43.Rh5+ Qh6 44.Rxh6#.
|Aug-08-19|| ||TheaN: Interesting that in most cases Q+R will dominate a sole Q in a king hunt; the problem is that even though she's the strongest piece, the queen is also the most valuable and a lot of defensive setups allow the Q+R side to win Q:R.|
Here, White has to defuse Qd1+ and Rb1+ by giving back the material <38.Rxg7+>. In itself not really a !, as White can't really do much else.
<38....Kxg7 39.Qg5+> whereas after 38....Kf8 Black prevents an immediate Qg5+ but with an additional rook White can find a few ways to win: the best probably is 39.Rg8+ Kf7 (Kxg8 40.Qg5+ similar to the game line; Ke7 40.Rh7+ and mate soon) 40.Rf5+!, this move is key to force Black to take the g-rook, 40....Kxg8 (Ke7 41.Qg5+; Ke6 41.Rg6+; both mate soon) 41.Qg5+ Kh8 42.Re8+ Kh7 43.Re7+ Kh8 44.Qg7#.
<39....Qg6> Kf8 (Kf7 is similar) perhaps challenges White to finish it but it's objectively worse than Qg6 as after 40.Rh8+ Kf7 41.Rh7+ Ke6 (Kf8 (Ke8 similar) 42.Qg7+ Ke8 43.Qg8+ Qf8 44.Qe6+ Kd8 45.Qd7#) 42.Rh6+ Kd7 43.Rxd6+ Kxd6 44.Qf6+ +- and White picks up everything.
However <40.Qe7+ Kg8 (Qe7 41.Rh7+ Kxh7 42.Qxf7+ with 43.Qf6+ +-) 41.Rg5 +-> is relatively easy to spot and Black has no time to take White's pawns off, with an easy win for queen.
|Aug-08-19|| ||malt: Black could have played 37...Rb1+
|Aug-08-19|| ||Sally Simpson: ***
I like these heavy piece endings. Rooks stomping around like brutal Ogres, nimble wicked Queens tiptoeing on the diagonals looking for a way to hurl an Ogre to smash though a cowering King's defensive shield.
Two Ogres wers dashed against the rocks in this game. (note 'Rocks' not 'Rooks'.)
Black had a good chance here to hold the game.
click for larger view
34....Rxe2 looks OK. 35. Kxe2 Qg2+ and Qxh1 it's still game on. (that that d6 pawn is countered by White's exposed King.) 35.Qxe2 Rxf3+ wins for Black.
Black missed it (move 34 is time trouble territory - maybe playing for a win.) and threw the other Ogre instead.
White, not to be outdone in the Ogre saccing stakes, hit back with their own Ogre sac and it was 1-0.
The moral of the story is:
Take advice from one who is older,
that before sacrificing an Ogre,
always look for one that is bolder,
That way you won't cry on a shoulder.
|Aug-08-19|| ||Ratt Boy: Look; if I got this within a minute, that means it was WAY EASY for a Thursday.|
|Aug-08-19|| ||Dionysius1: I like the theme of forcing the K away from defending the Q. Are/were the top GM's up to creating a theme just for the aesthetic value, once they knew they were winning?|
|Aug-08-19|| ||Breunor: On 27 Rb1:
1) +5.17 (25 ply) 38.Ke2 exf3+ 39.Kd2 Qxd6+ 40.Kc2 Rxg1 41.Qb3+ Kf8 42.Rf5+ Ke8 43.Qf7+ Kd8 44.Rd5 Rg2+ 45.Kb3 Rg6 46.Qxb7 f2 47.Rxd6+ Rxd6 48.Qb8+ Ke7 49.Qa7+ Kf8 50.Qxf2+ Kg8 51.Kb4 Rf6 52.Qd4 Kf7 53.Qd7+ Kg6 54.Ka4 Kh7 55.Qd3+ Kh6 56.Qc3 Kg6 57.Qg3+ Kh6
Losing move is 34 e4 which missed Rxe2:
1) =0.00 (28 ply) 34...Rxe2 35.Kxe2 Qg2+ 36.Qf2 Qxh1 37.d7 Rd8 38.Qb6 Qg2+ 39.Ke1 Qg3+ 40.Ke2 Qg2+
After 34 e4, we have:
1) +8.30 (24 ply) 35.d7 Rh2 36.Rxh2 Qxh2 37.d8=Q Rxd8 38.Rxd8+ Kf7 39.Rd7+ Kg8 40.Qd4 Qh1+ 41.Kf2 Qh4+ 42.Ke3 Qg5+ 43.Kxe4 Kh7 44.Kd3 a5 45.Rd8 Qg6+ 46.Kd2 Qf6 47.Qd3+ g6 48.Qd7+ Qg7 49.Qe6 b5 50.Kd3
2) +5.11 (23 ply) 35.Rdh5 Rxf3+ 36.exf3 Rb2 37.Rg1 Rb1+ 38.Ke2 exf3+ 39.Kd3 Qxd6+ 40.Kc2 Rxg1 41.Qe8+ Qf8 42.Rh8+ Kxh8 43.Qxf8+ Kh7 44.Qxf3 Kh6 45.Qxb7 Rg6 46.Qh1+ Kg5 47.Qg1+ Kh5 48.Qc5+ Kh6 49.Qe3+ Kh5 50.Qe4 Kg5 51.Qe7+ Kh5 52.Qc7 Kh6 53.Qf4+ Kh5 54.Qf5+ Kh6 55.Qh3+ Kg5 56.Qg2+ Kh6 57.Qh2+ Kg5 58.Qg3+ Kh5 59.Qe5+ Kh6
|Aug-09-19|| ||TheaN: Interesting about yesterday's puzzle (as there isn't much to discuss about today's re-re-cycle) how strong 35.d7! is. I'd say White erred playing 35.Rdh5?! even though it wins.|
The key is <35.d7 Rd8> the only move that defuses White's threat is Rh2 which is why engines give that, but after Rxh2 and d8=Q Black loses all counter play. Rxe2 doesn't work because of the same combination where it's #7 as Black's blocking f8.
The key after Rd8 (or Rxe2) is a very unique <clearance>. In fact, White has time and the means to set up a <clearance setup sacrifice>: after <36.Rh8+! Kxh8 (Kf7 37.Rxd8 +-) 37.Rh5+ Kg8> White just cleared a2-g8 by saccing Rh1 first, so <38.Qb3+ Kf8 39.Rf5+ Ke7 40.Rf7+ Kd6 41.Qb6+ +-> creates an inescapable mating net. White possibly didn't foresee allowing the diagonal check to be so destructive.