Oct-31-15
 | | Penguincw: Happy Halloween everyone.* And of course, it's the last day of October. So, what's your plan for the evening? :P Anyway, I didn't get this puzzle. I considered Rb7+, Rxa6, Qxc5, but not the move played in the game, or even the right idea. I have to say though, I almost thought 29.Qd2+ was like the most obvious answer ever. But of course, if a Saturday puzzle** has an "obvious" solution, you're probably overlooking something, and yeah, I missed the rook on c6. *You're welcome <everyone>. :) **If a Sunday puzzle is extremely easy, that might be because it's actually a Monday puzzle. This actually happened earlier this year in June: 25.?
click for larger view
S Kustar vs A Kranz, 1999. The actual Sunday puzzle was this:
37.../38...? of this game: Ponomariov vs L Bruzon Batista, 2011. |
|
| Oct-31-15 | | mel gibson: I tried this on DR4 64 bit & it played the same move at 29
but it ended up as a stalemate.
It was only on 3 seconds per move. |
|
| Oct-31-15 | | Mehem: 29.Rd4! is a nice tactics but it would have been anyway difficult to win if not Black's helping hand 31... hxg2? |
|
| Oct-31-15 | | ozu: Well I got the 1st move and rushed over to this page. I'm getting lazy |
|
| Oct-31-15 | | morfishine: <29.Rd4+> |
|
| Oct-31-15 | | diagonalley: ....well i saw that 29.R-Q4+ was playable... but failed to find a convincing continuation... nigh on impossible to foresee the game line :-( |
|
| Oct-31-15 | | agb2002: The material is identical.
Black threatens 29... Qd1+ 30.Qf1 Rxg2+ 31.Kh1 Qxf1#, 29... Rxb8 and 29... Qxg2+. The black king doesn't look very safe. This suggests 29.Rd4+, incorporating this rook into attack: A) 29... cxd4 30.Qxd4+ Ke7 (30... Kc7 31.Qa7#) 31.Qa7+ Rc7 32.Qxc7#. B) 29... Ke7 30.Rxg8 Qxg8 31.Qh4+ Kf8 (31... Ke8 32.Q(R)d8#; 31... f6 32.Qxf6+ Ke8 33.Rd8#) 32.Rd8+ Kg7 33.Qg5+ and mate in two. C) 29... Kc7 30.Rxg8 Qxg8 31.Rd3 with the idea of exploiting the future passed h-pawn. For example, 31... hxg2 32.Qxg2 Qxg2+ 33.Kxg2 Rb6 34.Rd2 Rb1 35.h4. That's all I can do today. |
|
| Oct-31-15 | | patzer2: Got 29. Rd4+! easy enough for my Saturday solution, but the strong winning positional play after the obvious 29...Kc7 30. Rxg8 Qxg8  (+0.69 @ 21 depth) eluded me.Apparently, 30...Qxg8 31. Rd1 (diagram below)
click for larger viewis one of those positions where the horizon effect doesn't allow the computer to initially evaluate just how decisive the position is until it reaches well over 30 plus depth of calculation. In the above position, Deep Fritz 14 initially gives it as only about a pawn advantage for White (+0.80 @ 26 depth). However, after the program plays out it's best line move-by-move at 25 depth and above, the evaluation gradually increases to decisive after 31... a5 32. Rd2 Qxg2+ 33. Qxg2 hxg2 34. h4 Rb6 35. Kxg2 Rb8 36. Kh3 Rh8 37. c4 Rh5 38. Rd6 Rh7 39. Ra6 Rg7 40. Rxa5 Rg1 41. Rxc5+ Kd7 42. Rb5 Rh1+ 43. Kg3 Rg1+ 44. Kh2 Rg4 45. h5 Rh4+ 46. Kg3 Rxh5 47. Rb7+ Kc6 48. Rxf7  (+2.81 @ 26 depth). Deep Fritz 14 improves slightly over White's 36. c4 (+7.13 @ 25 depth) with the alternative winning move 36. h7! (+11.30 @ 25 depth) when play might continue 36...Rh8 37. Rb1 Rxh7 38. Qxg2 Qd7 39. Rb7+ Kc8 40. Rxd7 Kxd7 41. Qg8 Rh3 42. Qxf7+ Kd8 43. Qf8+ Kc7 44. Qxc5+ Kb8 45. Qb6+ Kc8 46. Qxe6+ Kb7 47. Qxf5 with Fritz announcing mate-in-14. P.S.: Obviously strong GMs familiar with such positions have an advantage over those of us who don't initially recognize the true value of such "small positional advantages." |
|
| Oct-31-15 | | dfcx: I saw 29.Rd4+ and black can't take the rook because of 29...cxd4 30.Qxd4+ mating. But after 29...Qc7 I do not see any strong continuations for white. |
|
| Oct-31-15 | | Pinkerton: Knowing a very difficult continuation is to be made, Rd4+ is the only move there is. After that I'd bet Rxg8 has to be made since there's no sustained check on black K and the pressure on g2 needs relief. |
|
| Oct-31-15 | | Pinkerton: The strength of owning the d file is what I did not foresee |
|
| Oct-31-15 | | kevin86: White is about to take control of both wings! |
|
| Oct-31-15 | | varishnakov: I saw that 29.Rd4+ was possible and the rook could not be captured. After 29...Kc7 I could find nothing better than 30.RxR QxR and I understood the positional asset that is a controlled open central file that cannot be immediately contested, but then as this is a puzzle and I couldn't find a way to gain serious material advantage, I abandoned the line. Black can force a rook ending via check on g2. I will consider this puzzle gotten as it is the move I would play OTB for intuitive positional reasons that were proven correct in the game continuation. |
|
Oct-31-15
 | | FSR: I saw 29.Rd4+! Kc7! 30.Rxg8, but didn't realize that such a line could be considered a "solution." |
|
| Oct-31-15 | | dark.horse: I didn't get it, but I think the reason why 20.Rxg8 is strong is that it pulls the black Q away from a nasty check on d1. I didn't see that at first. |
|
| Oct-31-15 | | DarthStapler: I got the first move |
|
| Nov-01-15 | | patzer2: Need to correct something in my previous post.
The diagram in my post above is incorrect. After 31. Rd1 the correct (diagram below) position is 
click for larger viewDeep Fritz 14 indicates the strongest defense for Black is 31...Qxg2+ (+0.75 @ 27 depth) with the continuation following the erroneous diagram in my previous post. Black made it easier for White after 31...hxg2 32. Qd2 (+2.09 @ 25 depth). Perhaps even stronger is the Fritz continuation 31...hxg2 32. a4 (+2.40 @ 26 depth). |
|
| Nov-01-15 | | CHESSTTCAMPS: Tricky major piece middlegame. Black temporarily controls the g-file and threatens both 29... Qd1+ with mate in three and Qxg2+. The obvious way to counter these threats is 30.Rxg8, but white's temporary control of the back rank, creates an oportunity to improve the position of the Ra4: 29.Rd4+!
The rook can't be taken:
A.29... cxd4? 30.Qxd4+ Ke7 31.Qa7+ Rc7 32.Qxc7#
A.1 30... Rd6 31.Qxd6#
A.2 30... Kc7 31.Qa7#
B.29... Ke7? 30.Rxg8 Qxg8 31.Qh4+ f6 32.Qxf6+ Ke8 33.Rd8# C.29... Kc7 30.Rxg8 Qxg8 31.Rd2 looks like the best chance to play for a win (passed h-pawn after 31... Qxg2+). Time for review... |
|
| Nov-01-15 | | CHESSTTCAMPS: It seems several solvers were in the same boat - not sure of the best continuation after 29... Kc7 |
|
Kibitzing
