2024/04/18 DPA: "Backward Is The New Forward"

White to move.

If White could move Ne4, it would cut off communication between Black's Queen and Rook so the Rook would be en prise.

Since he can't get to e4 in one move, he could try to do it in two:  1. Nd2 is another Interference which blocks the Rook from defending the Bishop.  Also, note that White's back rank is adequately defended.

The Bishop is in no danger of being trapped.  In fact, it has 1. ... Bd4, a great central square which also adds an attacker to f2.

But White has 2. Ne4, simultaneously making the Rook undefended with the Interference tactic AND defending f2.

2. ... f5, hoping to dislodge the Knight, is met with 3. Kxe2.  Note that every square on the 2nd rank is controlled by White so the Black Rook has nowhere to go.

3. ... fxe4  4. dxe4 might be one way the puzzle ends.

Black also has 1. ... Bxa3, which gives Black a passer on a4, not an insignificant problem for White.  Maybe 1. Qa2 is better, which threatens 2. Rb1.  The Bishop can't move because the Rook will be lost and there is no way to defend the Bishop a 2nd time.  And 2. ... Re1+ fails because the Knight and King still guard e1 adequately.

Aah, I found a flaw in my original idea:  1. Nd2 Bxa3  2. Ne4 Rb2.  The Bishop capture allowed the b2 square to be freed up and defended by Black.

But White could play 3. Qa1.

1. Nd2 wins a piece for a pawn.

1. Qa2 wins the piece outright [or more].

That's not a huge difference but keeping the a3 pawn is important since Black's passer is so advanced.

Hmm, I see a problem:  1. Qa2 Rc2  2. Rb1 Qe2+  3. Kg1 Qxg2#.

1. Qa2 does indeed set up to win the Bishop but it cedes control of c2 which allows the Black Rook to slide over and make room for the Queen.

But White has the Intermezzo ["in-between" move] 2. Re1, chasing the Queen away from the e file, and then play 3. Rb1.

Oh, but that fails also:  say the Queen moves back 3. ... Qe8  4. Rxb2 Qe2+.  White is X-Ray defending e2 but Black deploys a counter-measure known as The Lead Shield where he inserts another piece [the Queen] into the attack and uses the shield [the Rook] to block the X-Ray defense of e2.

Since White can't allow this, 1. Qa2 would lead to a repetition and a draw.

But what about 1. Qa2 Rc2  2. Re1 Qd7  3. Qb1:  now the Rook has nowhere to go and White, not Black, controls e2.  And Black has no way of defending the Rook, as the d3 pawn blocks the light-squared diagonal.

Both were wrong:  1. Ng1 [the BNM <Backward Knight Move>] Rxf2+  2. Kxf2 Bd4+  3. Kf1 Qe3  4. Nh3

The key was seeing the BNM, something often overlooked as an option [moving backward has the negative connotation of retreat, which is incorrect.  Rather, think of it as "repositioning to a better square"].  Once the Solver sees this, the rest follows naturally as the Rook is trapped.

The problem with my 2 solutions was not visualizing the board after 3 moves and missing key defensive moves available to the opponent.  That and I never even considered the BNM.