< Earlier Kibitzing · PAGE 3 OF 3 ·
|Jul-28-07|| ||AlexandraThess: Easy one. I spent 30 secs for calculating the variants after 35.Bxh6 but as soon as I found the refutation I switched to the right move 35.Rxc6.|
|Jul-28-07|| ||Fezzik: I love this one! Yes, it is definitely a 3.5+ star puzzle, and yes, it is easy if you know your endgames well. |
However, take a look at how many moves ahead a computer would have to look to discover the right moves and then congratulate yourself on being human if you got this one quickly!
We humans may find the right solution fairly quickly, but how many would play it against, say, Fritz (or a Grand Master)? Naiditsch is always close to the top tier of world class players and he showed it brilliantly with his understanding of the connected passed pawns against the lone rook.
(Note that in order for this tactic to work, the Black king had to be driven away from the kingside.)
Again, this is a 3.5-5.0 star puzzle, because it is insanely difficult to <calculate> all the variations. However, we humans don't need to calculate as much as computers do. I found it <relatively> easily, but then I'm not a computer.
Great choice for a Saturday/Sunday puzzle, cg.com!
|Jul-28-07|| ||Marmot PFL: Easier than yesterday. Most experienced players know how strong the connected passed pawns are once they advance that far, and fezzik is right that not so much calculation is required. The black king is just too far away.|
|Jul-28-07|| ||willyfly: Black is a up - after I tried a few lines beginning with 35 g5 it seems like White always runs into trouble after Black's joins in on the action either by way of e7 or xe5 so I thought it might be a good idea to remove the with 35 xc6 then xc6 moves the Black even further from the promotion promenade on the Kingside - White's can now control the Queening square and it should not be too difficult for White to get a - let's look now and see if I'm on the right track|
okey - it's the best I've done on a Saturday puzzle
|Jul-28-07|| ||zanshin: Just to confirm what you guys already know, Fritz had a hard time with this puzzle. As far as 18-ply, the position was evaluated as equal with recommended moves of 35.Rd1 or Rg1. Only at 19-ply did it find 35.Bxh6 (1.44) and Rxc6 (1.34). At 21-ply, Bxh6 still led Rxc6 (2.0 to 1.8).|
|Jul-28-07|| ||zanshin: Just for completeness (Fritz 10, 21-ply)
1. (2.06): 1.Bxh6 Nxe5 2.Bf4 Ng6+ 3.Kg5 Nxf4 4.Kxf4 Rh8 5.Ke5 a6 6.Rh1 b5 7.axb5 axb5 8.Kf6 Rf8+ 9.Kg7 Re8
2. (1.84): 1.Rxc6 Kxc6 2.Bxh6 Kd7 3.Bd2 Rf7 4.g5 Ke8 5.h6 Rf1 6.g6 Kf8 7.Bb4+ Kg8 8.Be7 a6 9.h7+ Kg7
|Jul-28-07|| ||Sneaky: What do you guys think of this assessment:
Note that now 36.Bf4 is no big deal due to ...Ng6+
Also note that Black is threatening to take on d3 next, where the central passers may provide enough counterplay for that nasty g&h pawn duo.
|Jul-28-07|| ||Creg: So many of us see that today's puzzle is fairly easy, but it is <Fezzik> who explains things best. It's not so much that it is easy, as the position is understood. It shows, as <Fezzik> points out so well, how humans see things compared to computers. Our world is so computer centric anymore, and in the world of chess too many players become dependant upon them that they never learn the principles of the game.|
Here we see where endgame study allows one to understand the power of advanced connected passed pawns. A distanct king and a lone rook who cannot stop both pawns on its' own, shows how humans see the combination quickly.
Computers on the other hand cannot visualize this, they must calculate every move just like a beginner does when they first learn the game. Computers just happen to do it at a phenomonal speed. :)
|Jul-28-07|| ||realbrob: I was quite satisfied because I had got it in a couple of minutes, but maybe it wasn't so difficult after all. At first I thought of 35.Bxh6, with good chances for the White king and passed pawns. Then I realised that if the rook couldn't stop the White king it was better to remove Black's knight from the board. So 35.Rxc6 Kxc6 (now the Black king is too far away to try and help its rook) 36.Bxh6. Now I calculated some variations in which Black actually accepted the sac, and they were winning for White. I guess that if Black doesn't take the bishop it doesn't change the situation a lot.|
|Jul-28-07|| ||realbrob: Maybe we could say this is difficult because a total beginner won't even consider sacrificing the exchange and a piece if he can't find a mate in 2 or something like that.|
|Jul-28-07|| ||4i4mitko: strange this was solved very quickly|
|Jul-28-07|| ||outplayer: I thought about 35.Rxc6 but didn't find the idea as I did not see 36.Bxh6 - a real surprising move for me. I think I should spend more time on this.|
|Jul-28-07|| ||patzer2: For today's puzzle solution 35. Rxc6!! is the first of two consecutive pseudo-sacrifices, whose purpose is to allow two connected passed pawns on the King side to pass.|
|Jul-28-07|| ||lopium: I found the two first moves very quickly but this was only luck I can assure.|
|Jul-28-07|| ||playground player: I guess the computers never got that elementary chess lesson that in the endgame, two connected passed pawns beat a rook every time.|
|Jul-28-07|| ||triangulation: wow! got it immediately . first time i've found a saturday puzzle so quickly.|
|Jul-28-07|| ||dzechiel: White to move. Very difficult. Black is up a pawn, but it's doubled. The g- and h-pawns look like they are ready to run.|
So, immediately I want to sac my bishop for black's h-pawn AND my rook for the knight (to bring the black king away from the king side). Then I think I can get the black rook for one of my pawns and I can promote the other to a queen. I'm going to try some sample variations:
35 Rxc6 (do this first as 35 Bxh6 allows 35...Nxe5) Kxc6 36 Bxh6 Rxh6 37 g5 Rh8 38 g6 and I think black resigns! The threat is 39 g7 Rg8 40 h6 and it's all over for black. If 38...Rg8 then 39 Kg5 and you run the h-pawn in. The black king is out of the picture.
Knowing the power of a pair of advanced passed pawns helps solve this one in no time. Time to check.
|Jul-28-07|| ||tallinn: <Gilmoy, aazqua suggest pushing the g-pawn instead of white king advancing to g5> Pushing the g-pawn is loosing:|
Rxc6 Kxc6 Bxh6 Kd7 g5? Ke8 (or Ke7) and the black king will come for rescue. White won't be able to move the g-pawn further and blacks queenside pawns will decide the game.
|Jul-28-07|| ||yalie: this may be tough for a computer, but looks really easy for a human - bxh6 to get the connected pawns going against the rook - but before that rxc6 to
1. prevent the knight from jumping into the fraw with, say, nxe5
2. push the king further away from the queening pawns.|
time to check if i missed something
|Jul-28-07|| ||fm avari viraf: There are two obvious lines 35.Rxc6 & Bxh6 but the latter would allow Black to play either 35...Nxe5 or ...Ne7 with some resistance. Hence, 35.Rxc6 is a K.O. move rendering Black's Rook null & void.|
|Jul-28-07|| ||unixfanatic: I was in a rush and just guessed either Rxc6 or Bxh6 in about 15 seconds - they just looked right! Actually, I thought it was Bxh6; it's a shame I didn't have a little longer to calculate!|
|Jul-28-07|| ||bogo78: <Sneaky: What do you guys think of this assessment: 35.Bxh6? Nxe5!! unclear> I've run it with shredder here is what it indicates. Indeed this will complicate matters quite a lot, but its not due to Nxd3 nor to Nf3+. Of course white 's reply to Nxe5 is 36 Bf4 Now its 36...Ng6+ that seems to provide the best chance for equality. if you want me to post the lines just let me know. just as a summary in the other two lines (the ones you mention) white still queens and in many lines mates on the back rank once this is accomplished.
Back to 36.. Ng6+ 37Kg3 Nxf4 38 Kxf4. Now this is indeed unclear but engines give + 1.5 advantage or so.|
|Jul-28-07|| ||Sneaky: <bogo78: I've run it with shredder here is what it indicates. Indeed this will complicate matters quite a lot 36 Bf4 Ng6+> I see -- I thought that Ng6+ resource rendered the Bf4 void, but apparently it's the critical line. <if you want me to post the lines just let me know.> Nah, not important--thanks, though.|
FM Avari summed it up best: You can play Rxc6 and leave Black with absolutely no chance for counterplay, none, zilch, nada -- if you try to get fancy with Bxh6 you then are forced to go on to win a very complicated ending. Therefore Rxc6 is a thousand times better than Bxh6 even though the computers may rate them about equal. So this puzzle is good in the sense that there is only one truly correct solution.
|Jul-28-07|| ||bakuazer: i considered the move and thought it is winning but wasn't sure. it is clear that black (rook) is in troule to stop the pawns. but somehow i couldn't make up my mind while thinking on the puzzle.|
|Jul-30-07|| ||kevin86: I answered this one correct-at least in spirit. The idea was to get the two connected pawns against the rook with no interference from the other pieces. First chop off the knight. Then sac the bishop to clear out the black pawn. Now,with the two pawns-aided by the king-and the black king too slow to arrive,the win is child's play (even without Charles Lee Ray).|
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