Black to move. Can black hold this?
N7/7r/1PP1K3/8/2p5/8/8/k7 b – – 0 1
White to move. Can white win this?
N7/7r/1PP1K3/8/2p5/8/8/k7 w – – 0 1
Chess Daily News from Susan Polgar
- About Us
- Chess Improvement
- Chess Puzzles
- Chess Research
- College Chess
- General News
- Home
- Major Tournaments
- News
- Polgar Events
- Privacy Policy
- Scholastic Chess
- SPICE / Webster
- Susan’s Personal Blog
- Track your order
- USA Chess
- Videos
- Women’s Chess
- Contact Us
- Daily News
- My Account
- Terms & Conditions
- Privacy Policy
Doesn’t c7 and b7 just win? I don’t really understand how this is a puzzle. :p
Oh, I like this!
It seems to me that pawn moves only draw.
b7,Rxb7,cxb7,c3,b8(Q),c2 and the N is too far away to change the drawn bishop pawn v Q stalemate set-up.
or c7,Rxc7,bxc7,c3,c8(Q),c2 draws as above, while c8(R),b2 is still a draw.
but the winning move is Nc7!, with 2 possibilities.
Nc7!,Rxc7,bxc7,c3,c8(Q),c2,then Q checks on the a and b files, then with Q on c3 and the white K on b1, must not take the c2 pawn straightaway but gain a tempo with one K move and take the pawn only when it promotes.
or Nc7!,c3,Nb5,c2,Nd4,c1(Q){N is slightly better},Nb3 and the pawns beat the rook.
Rook checks at any stage by black do not achieve anything.
Yes, white just needs to play 1. c7 to get an inevitable promotion.
If 1…Rxc7 then 2. bxc7 and promotion is unavoidable. White will win with a queen and knight verses a pawn 2 squares from promotion.
If 1…Rh8 then
2. b7 c3
3. c8=Q Rxc8
4. bxc8=Q
and white will win.
Did I miss anything?
Ra7 and white’s knight has nowhere to escape nd after that easy win for black
Was about to write out my comment, when some already appeared. Let’s talk about Goose’s comment before proceeding, however, since I had the same idea at one point.
Goose, at the end, suggested 1.Nc7 as a way for white to win, but this will only draw:
1. Nc7? c3! (Rc7?? 2.bc7+-)
2. b7
The line 2.Nb5 also draws- Goose overlooks that in the critical line, black can queen with check preventing the knight fork: [2.Nb5 c2 3.Nd4 Rh6! 4.Kd7 Rc6!! and now 5.Kxc6 is met with c1Q with check]. Continuing:
2. …..c2
3. b8Q c1Q
4. Qa7 Kb1
5. Qb6 Ka1
6. Qa5 Kb1
7. Qb4 Ka1
8. Qa4 etc. White will have to take the perpetual just to keep from losing, I think. I can’t even say for sure this line isn’t lost for white without a much deeper look, but it is definitely not winning.
With 1.Nc7 out of the way, let’s take a deeper look at the pawn pushes when white moves first, and we will again use Goose’s comment as the stepping off point.
1. c7 Rc7 (alternatives later)
2. bc7 c3
3. c8Q? c2!
And this is a classic drawn position since any time white threatens to capture at c2, the black king retreats to a1 for the stalemate. However, white can throw a wrench into this plan by under-promoting to a rook at move 3 in the line above:
3. c8R! Kb2 (gotta protect c3)
4. Nb6! c2 (nothing holds)
5. Nc4 Kc3
Nothing better. If Kc1, white just double attacks and wins the blocked c2 pawn with Na3/e3. If Ka2/a1/b3, white also double attacks the unblocked c2 pawn with Ne3 and wins it since the black king can’t protect the new queen at c1. Finally, Kb1 loses to Na3+. Continuing:
6. Na3 and the c2 pawn falls.
So, in this line, we must back up to black’s first move:
1. c7
Black has three options- c3, Rh8, and Rh6+. In order:
1. …..c3
2. c8Q c2 (nothing better)
3. Qc2
And now black’s only hope is the repetition draw because white’s king cannot take the rook, however, this isn’t going to save black in this position due to the presence of the second white pawn. For example:
3. …..Rh6
4. Kf5 Rh5 (Rf6 5.Kg5 wins)
5. Kf6 Rh6
6. Qg6 and it is over.
Now, let’s discuss the two rook moves:
1. c7 Rh8
2. b7 c3 (what else?)
3. c8Q Rc8
4. bc8R! Kb2
I know, we saw this earlier, but for explicitness:
5. Nb6! c2
6. Nc4 and the double attack on the pawn by either Na3 or Ne3 is unstoppable and the pawn must fall.
Finally, let’s look at 1. …Rh6+:
1. c7 Rh6
2. Kd5 c3 (what else better?)
3. c8Q and we already know this is lost.
So, as white, white can win by pushing c7, but needs to under-promote at c8 in critical lines where black has already given up the rook.
In my next comment, we will discuss the puzzle where black moves first.
In my previous comment, I think I showed that white wins with 1. c7. Now let’s discuss the position when black moves first. The obvious place to start is with the pawn push:
1. …..c3
2. c7 Rc7
I think 2. …Rh6 draws, too, but Rc7 should as well, and uses material I have already analyzed in the previous comments:
3. bc7 c2
And it does not matter what white promotes the pawn to- rook or queen- the black pawn is one move further down the board than in the lines where white moved first, so the under-promotion doesn’t win any longer. So, white will have a queen and knight vs queen, but that is also a technical draw.