Troitsky 1911
White to move. How should White proceed?
8/2B5/p4q2/4N2p/4Pp1k/8/P5PK/8 w – – 0 1
Chess Daily News from Susan Polgar
A classic chess tactic
Troitsky 1911
White to move. How should White proceed?
8/2B5/p4q2/4N2p/4Pp1k/8/P5PK/8 w – – 0 1
A draw is assured for white.
1.Nf3+ Kg4
2.Ne5+ Kh4
(2… kg5 3.Bd8 Qxd8 4.Nf7+ fork)
draw by repeatetion.
If there is a win I leave it for evening study.
White has several ways to draw!
>1.Bd8!!.Qxd8.2.Nf3+.Kg4.3.Ne5+.Kh4 etc with a perpetual check! (if 3…Kg5.4.Nf7+ and 5.Nxd8 and white wins)
>1.Nf3+.Kg4.2.Ne5+.Kh4 etc for a draw by perpetual checks (If 2….Kg5.3.Bd8!.Qxd8. 4.Nf7+ followed by 5.Nxd8 and white wins!)
Harry
In the morning I had very little time for analysis.I recognized Bd8 and N fork under certain positions but how to force those positions?
Mobility anlysis for Black
King:king can go to g5 only and white’s Bd8 works.
Queen:Q has to control d8 square.So only possible destinations for Q are g5,e7,f8 and h8. With Qe7 there is direct N fork from g6.Qg5 is met by Nf3 fork.Qf8 and Qh8 are met by Bd8.
So virtually K and Q are immobile.
Regarding Ps f3 is met by g3+ and Bd8.Only “a”Pis mobile.
Mobility analysis for white
N is required at e5 to control g4 and B has to control d8 as well as e5.So both are immobile.Only “a” P is mobile.
Now white has to force zwugzwang on black.This is the hands of white P whether 1.a3 or 1.a4 ?
1.a4 a5 and it is white who is in zwugzwang.So the right move is
1.a3 a5
2.a4 now black is in zwugzwang and has to move either K or Q and he loses.
It is assumed that the N and P ending after capturing Q is win for white.
At first I saw a quick draw for white:
1.Nf3+ Kg4, 2.Ne5+ Kh4 (2…Kg5? 3.Bd8! Qxd8 4.Nf7+)
But this could hardly be the solution, and after looking a bit further I discovered that Black is almost in zugzwang:
1…Kg5 2.Bd8 +-
1…f3 2.g3+ Kg5 3.Bd8 +-
1…Qg5 2.Nf3+
1…Qe7/Qf8/Qh8 2. Ng6+
Other queen moves lose to 2.Bd8+ (or trivially to BxQ). So all White has to do is keep the status quo and wait until blacks
alternatives are exhausted:
1.a3! a5 (only move that does not lose instantly)
2.a4! and Black is out of ideas
How about good ole fashioned a3? Black could try to get cute and play …a5, but white can lock that pawn up with a4 and then black is left with a bunch of really bad moves.
This was fiendishly difficult! It took me many minutes to understand this was a zugzwang type problem, even though I am actually quite familiar with Troitsky puzzles.
Ultimately, what white wants is for black to be forced to play f3 with the same alignment of white pieces, kingside pawns and king. The difficulty arises from figuring out that black’s queen has little maneuver room. I finally found the thread by working through the issues with an immediate Nf3:
1. Nf3 Kg4
2. Ne5 Kg5
Of course, black’s king can return to h4. However, I want to demonstrate, first, how black’s choices are constrained by the main threat. Continuing:
3. Bd8 Qd8 (what better now?)
4. Nf7 and the fork on the king and queen wins the game for white.
Of course, the problem above is that black’s king isn’t forced to g5 for that skewer and knight fork. It would be really nice if white could, at some point, play g3 check to take that square away with the knight on e5 and the bishop on the a5/d8 diagonal, but not on d8 itself. This lead me immediately to studying the moves of the a-pawn as waiting moves. Let’s look at a4 first:
1. a4 f3
This isn’t the optimal move, as I will describe below. We have shown above that 1. …Kg5 loses to 2.Bd8. I will discuss the queen moves for black at move 1 later, plus the correct move black should have played here. Continuing:
2. Nf3 Kg4
3. Ne5 Kh4 (Kg5 4.Bd8 wins)
4. g3 Kg5 (only move now)
5. Bd8 and Nf7 will follow to win the game for white.
Now, at move 1, black must keep the queen guarding d8 since if he allows Bd8 with check, the queen must block the check since the king on h4 will have no legal move. But the only two “safe” squares the queen can move to to accomplish this are e7 and g5, but those two moves allow knight forks from g6 and f3 respectively. So, this leaves only one move for black:
1. a4 a5!
And now black has forced white to take the draw by repetition since there is no way to force black to make a move that loses.
This, of course, means white wins 1. a3 since, then, white can reply to a5 with a4 and force the move order back to black.
Naturally the eye is drawn to the King and Queen on the same diagonal But if 1.Bd8 of course the Queen simply takes the Bishop and there’s no Knight fork. The Knight can attack the Queen at f7 or can check at g6 but no fork. If only the Bishop could check at e7 instead!
But it’s also apparent that the Black King doesn’t have many squares available to it and also if the Queen moves off the diagonal then the Bd8 check leads to mate (or loss of the Black Queen). So are there zugzwang possibilities?
1. a3 …. What happens on any move other than 1… a5, 2. a4 ?
Queen moves:
Staying on the diagonal:
1…Qe7, 2N g6+; 1… Qg5, Nf3+
Queen moves off the diagonal leads to 2. Bd8+ unless the Queen goes to a square that guards d8: but either 1…Qf8 or 1…Qh8 allow the fork at 2.Ng6 again!
King moves:
1…Kg5 but now White does have a fork after the Bishop pin 2. Bd8 Qxd8, 3. Nf7+
Finally 1…f3, 2. g3+ Kg5, 3. Bd8 Qd8, 4. Nf7+ again
So 1. a3 a5, 2. a4 but now it’s zugzwang Black is out of other moves and has to play one of the losing moves above.
– Craigaroo
Black must repeat moves. If Black doesn’t it loses.
I suppose my analysis is incomplete without the possible K+P endgame, which I should’ve suspected since the problem is by Troitzky who was famous for K+P studies. But I can’t see that far. It looks like a win for White to me after
1. a3 a5, 2. a4 f3, 3. g3+ Kg5, 4. Bd8 f2, 5. Bx f6+ Kx f6, 6 Nd7+ Ke7, 7. Kg2.
Good thing White’s King was in the “magic square” . I think White wins this endgame up the extra pawn.
– Craigaroo
1. a3! is zugszwang …as any queen move will lose the queen by knight fork or be mated by the book shop, while a pawn move by black, white will just make a waiting move …like a4.
To add on my previous comment a black king move to g5 will lose the queen by Bd8 as the queen is force to take then Nf7+ wins the queen.
Yeah…In the morning I was at work place and didn’t had much time to spend on this. Now with a different mind set I could get the Idea. The theme is to create zugzwang.
1.a3!! (Not 1.a4?…Because of 1…a5 and now white has to move. with present text white will make last move with a pawn and creates zugzwang.)Continuing,
1….a5 (If Black moves King or Queen he will loose the Queen or Checkmate. Because white has a dangerous knight fork.) Continuing,
2.a4 f3 (Other moves will leads to loss of queen.)
3.g3+! Kg5 4.Bd8! QxB (No other way…)
5.Nf7+ and the Queen is forked. Gradually white can promote one of his pawns with the help of knight..
1. a3! a5
A. 1. … Kg5 2. Bd8! Qxd8 3. Nf7+ 1-0;
B. 1. … f3 2. g3+ Kg5 3. Bd8 Qxd8 4. Nf7+ 1-0;
C. 1. … Qe7 2. Ng6+ 1-0;
D. 1. … Qg5 2. Nf3+ 1-0; 1. … Qe6 2. Bd8+ 1-0; etc.).
2. a4 and Black has no choices left. The continuation will go along the lines described above.
I think you can move Nf3, if Kg4 you move Ne5. You can draw or wait until black moves Kg5
I think you can move Nf3, if Kg4 you move Ne5. You can draw or wait until black moves Kg5
White can draw with 1. Bd8 Qxd8 2. Nf3+ Kg4 3. Ne5+ and Black should return the king to h4 for a perpetual. If Black exits with 3. … Kg5, White wins with 4. Nf7+ forking the queen.
I almost immediately found the forced draw:
1. Bd8 Qxd8
2. Nf3+ Kg4
3. Ne5+
and the King has to return to h4, allowing the perpetual, because
3. … Kg5 ???
4. Nf7+
winning the Queen.
But that’s too obvious, more so than you would expect from Troitsky. So there must be a more subtle solution leading to a win for White. I haven’t found it yet, though.
The queen cannot leave the diagonal where her king is because of a Bishop check that mates.
So, White has to make (1) a3, forcing black to make the move (1)…. a5; (2) a4. Now Black has to move either his, Queen, pawn or King.
a) Qe7 gets him into a knight fork on g6
b) Q g5 gets him into a knight fork on f3
c) Qh6 gets him mated by Bd8
d) f3 gets him mated with g3
e) Kg5 gets his queen pinned by Bd8…QxB and then gets him forked by Nf7
If 1 a3 f3 2 g3+ Kg5 3 Bd8 f2 4 Bxf6+ Kxf6, then 5 Kg2? Kxe5 draws, so 5 Nd7+ Ke7 6 Kg2 Kxd7 7 Kxf2 is necessary to hold the e-pawn and win.
Further, 1 a3 f3 2 Bd8 (2… Qxd8 3 g3+ Kg5 4 Nf7+) saves needing to see 5 Nd7+ in the above line.
-BW
I had two misses in this puzzle.
First I never thought of 1.Bd8 to draw.I thought black will win in that case.Harry and Bob showed it could draw.
Second Yancey’s line 1.a3 f3 2.Nxf3+ .This is nice thinking of endgame.I had some illusion f4 could provide escape route for black of course without analysis.I opted for immediate 2.g3+.I had thought white K could handle f pawn.My line is not incorrect but Yancey’s is better.