I've decided, since I have nothing better to do, that I'm going to post
an interesting problem position, key move, or endgame study here
once a week. No one else seems to be doing much here so... here's
one for this week! It's probably THE BEST chess puzzle/problem EVER.
I don't know that *I* understand it in all it's complexity. Some have
called it the Diagram of the Century. It's probably the most
complicated and beautiful problem I've ever seen.
FEN:
Bq1B1K2/3PpN2/P3Pp2/P1p2P2/2Pk1b1R/1p6/pN1P1P2/QR6 w - - 0 1
White to Mate in 4!
Originally posted by ReinGood one Rein!
I don't know that *I* understand it in all it's complexity. Some have
called it the Diagram of the Century. It's probably the most
complicated and beautiful problem I've ever seen.
FEN:
Bq1B1K2/3PpN2/P3Pp2/P1p2P2/2Pk1b1R/1p6/pN1P1P2/QR6 w - - 0 1
White to Mate in 4!
I'm still working on it!
Perhaps I don't fully understand this either. It is indeed complex.
The interesting thing about this puzzle is that black's king cannot
move anywhere in the first place. It should be as simple as checking
the king, without moving any of the 'pinning' pieces. The obvious
piece to check the king with would be the rook on h4 (taking the black
bishop). However, this is defended by the black Queen.
Therefore the task at hand is to force the black queen to move. This
can be done with a6-a7. The two obvious reactions from black would
be either to take the white bishop at d8, checking the king, or to
move the queen to d6 (to tempt white to move its knight at f7 from
pinning the black king). Both options can only buy time for black as
long as white doesn't take the queen with the knight at f7. To respond
to the first option, white should move its king, while to the second
white should move its rook from b1 to e1 (threatening another
method of checkmate: Rb1-e1 Qd6-e5, Nf7-e5 f6-f5, Re1-e4 mate).
Either way it should be mate within four moves.
I apologise for my poor PGN syntax. I may be completely incorrect,
after all I am only a very amateur chess player. However, I cannot see
any other way to achieve this nor can I see any way out for
black. 😀
You're dead on about the Queen. It guards f4, so why not make it
move? After a7, then black has a few queen moves... First, he has two
queen moves that *don't* defend f4, but after both White is in time:
1...Qxa8 2.Rxf4+ Qe4 3.a8=Q Qxf4 4.Qd5 mate. Or: 1...Qxd8+ 2.Kg7
and now 2...Qg8+ 3.Kxg8 and 4.d8=Q mate or 2...Qxa8 3.Rxf4+ Qe4
4.d8=Q mate or 2...Qc7 3.d8=Q+ Qxd8 4.Rxf4 mate.
So we turn to Queen moves that do defend Bf4. There are three,
and against all three White is in time: 1...Qc7 2.Bxc7 axb1=Q 3.d8=Q
mate, or 1...Qd6 2.Re1 Qe5 3.Nxe5 fxe5 4.Re4 mate or 1...Qe5
2.Bxe7 Qd6 3.Nxd6 Ke5 (otherwise Bxf6 mate) 4.Nd3 mate.
But that's not all! What about another move that defends against
mate? What about axb1=Q?
Rein
If that happened I would play a7xb6=Q.
From there I can see 5 possible options for black (some variances of
each other):
Taking moves:
1) ...Qxf5, Qxf4 Qxf4, Rxf4 mate
2) ...Qxb2, Qxb3, Qxa1, Rxf4 mate (this is the most different)
Non-Taking Moves:
1) ...Qe4, Qxf4 Qxf4, Rxf4 mate
(Notice each time Rxf4 provides the mate. With the last two this
method is also possible. However I will show a different one that is
possible only with these moves)
2) ...Qc2, Qd6+ e7xd6, Bd6 mate
3) ...Qd3, Qd6+ e7xd6, Bd6 mate
With all five of these options mate is achieved in exactly four moves.
Any other move by black would result in instant checkmate with Rxf4.
It is indeed an interesting puzzle 🙂
We're not quite done!
There is almost a moral lesson here: we get access to beauty through
the simple virtue of scrutiny. Have we really checked all of Black's
defences? After 1.a7, we checked all the Queen's moves, and the
promotion: axb1=Q What else could there be to check? Well, the
promotion is the wrong wording: Black has four different promotions.
But what good could a promotion to rook do him? Let's just have a
look: 1.a7 axb1=R 2.axb8=Q Now, there is no 2...Qe4, but Black still
has his other defence: 1...Rxb2, making d3 and c4 available to his
King. And if White now continues as before, with 3.Qxb3, it is
stalemate. So, what to do?
Rein
Wow, I didn't know a puzzle could be so complicated!
The move you are looking for is a7xb8=R. This would not cause a
stalemate because the pawn at c4 is not defended. The folloeing
move sequence would look something like this:
Rxb3 Kxc4, Qa4 mate
However, if you don't mind me quoting you, "we're not quite done!"
A similar problem arises if black promotes to a bishop or a knight. A
bishop could block white's attack at f4, while a knight could take the
pinning pawn at d2. The interesting part is that white should promote
to the same piece that black does!
With the knight promotion, white needs a knight to threaten an attack
from c6 because if black takes the pawn at d2 the white queen will be
held up 'replacing' it:
...Nxd2, Qc1 Ne4, Nc6 mate
With the bishop promotion, white needs a bishop to introduce a new
dimension to white's attack. Black can use two bishops in a row to
defend its king. Therefore, a slightly different attack is required:
...b1e4, bxbf4 bf5, be3 mate
I apologise for the brevity of this post: I didn't want to give you so
much to read that you got bored half way through 😉
