Editing Chess problem (section)

==Examples==
{{Chess diagram
| tright
| Thomas Taverner <br />''Dubuque Chess Journal'', <br />1889 (1st Prize)
|  |  |  |bd|rd|rd|bd|
|  |  |nl|  |  |  |  |bl
|  |  |  |  |  |  |  |
|  |  |pd|  |  |  |  |ql
|  |  |pd|  |  |kd|  |
|  |  |  |  |  |pl|  |
|  |  |  |  |pl|  |kl|rl
|  |  |nl|  |  |rl|bl|
| White mates in two
}}

To the right is a directmate problem composed by Thomas Taverner in 1881.

The key move is 1.Rh1.  This is difficult to find because it makes no threat – instead, it puts Black in [[zugzwang]], a situation in which the player must move, yet every move leads to a disadvantage. Each of Black's nineteen legal replies allows an immediate mate. For example, if Black defends with 1...Bxh7, the d5-square is no longer guarded, and White mates with 2.Nd5#.  Or if Black plays 1...Re5, Black blocks that escape square for his king allowing 2.Qg4#. If Black plays 1...Rf6, then 2.Rh4#.  Yet if Black could only pass (i.e., make no move at all), White would have no way to mate on his second move. The full solution is as follows:

:1 Rh1{{chesspunc|!}} and now:
::1...Bxh7, 2.Nd5# (unguards d5)
::1...Bf7, 2.Qf5# (interferes with rook’s guard of f5)
::1...Be6, 2.e3# (interferes with rook’s guard of e3)
::1...Bd5, 2.Nxd5# (unguards d5)
::1...Bxc7, 2.Rh4# (unguards h4)
::1...Be7, 2.e3# (interferes with rook’s guard of e3)
::1...Bf6, 2.Qf5# (interferes with rook’s guard of f5)
::1...Bg5, 2.Qh2# (blocks king’s flight to g5)
::1...Bh4, 2.Rxh4# (unguards h4)
::1...Rf7, 2.Nd5# (interferes with bishop’s guard of d5)
::1...Rf6, 2.Rh4# (interferes with bishop’s guard of h4)
::1...Rf5, 2.Qxf5# (unguards f5)
::1...Re7, 2.Rh4# (interferes with bishop’s guard of h4)
::1...Re6, 2.Nd5# (interferes with bishop’s guard of d5)
::1...Re5, 2.Qg4# (blocks king’s flight to e5)
::1...Re4, 2.fxe4# (allows pawn capture discovering check)
::1...Re3, 2.Bh2# (blocks king’s flight to e3)
::1...Rxe2+, 2.Nxe2# (allows capture on unguarded square e2)
::1...c3, 2.Nd3# (unguards d3)

The thematic approach to solving is to notice then that in the original position, Black is already almost in zugzwang.  If Black were compelled to play first, only Re3 and Bg5 would not allow immediate mate. However, each of those two moves blocks a flight square for the black king, and once White has removed his rook from h2 White can put some other piece on that square to deliver mate: 1...Re3 2.Bh2# and 1...Bg5 2.Qh2#.

The arrangement of the black rooks and bishops, with a pair of adjacent rooks flanked by a pair of bishops, is known to problemists as [[Pipe organ|Organ Pipe]]s. This arrangement is designed to illustrate the effect of mutual Black interferences: for example, consider what happens after the key if Black plays 1...Bf7. White now mates with 2.Qf5#, a move which is only possible because the bishop Black moved has got in the way of the rook's guard of f5 – this is known as a ''self-interference''. Similarly, if Black tries 1...Rf7, this interferes with the bishop's guard of d5, allowing White to mate with Nd5#. Mutual interferences like this, between two pieces on one square, are known as [[Grimshaw (chess)|Grimshaw]] interferences, and are the theme of this problem. The problem exhibits four such interferences, on squares e6, e7, f6, and f7.

{{Chess diagram
| tright
|
|  |  |  |  |kl|  |  |
|  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |
|  |  |nl|  |  |nl|  |
|  |  |  |ql|  |  |  |bl
|  |  |pl|  |rl|  |  |
|pd|pd|pd|pd|pd|pd|pd|pd
|rd|nd|bd|qd|kd|bd|nd|rd
| White mates in one move!
}}
Some problems involve a humorous trick or twist. The problem to the right, shown in Norwegian broadcaster [[NRK]]'s airings from the World Championships in Dubai 2021, calls for White to mate in just one move. The trick is to recognize that despite the arrangement of the Black men, the board is actually viewed from the White side, as shown by the black king standing on a square of its own color, rather than on the opposite color as in the standard opening position. Thus the solution is 1.Nd3#; the knight is ''behind'' the black pawns and cannot be captured.