2024/03/30 DPA: "On The Menu, A Pair Of Skewers"
White to move.
Black's King is ill-placed. But the key attacking square d6 is covered by the Knight.
White can't play a setup move like 1. Kb3 to prep 2. Qb4+ due to either 1. ... Nd2+ or 1. ... Qe6+.
2 promising checks exist: 1. Qa7+ and 1. Qf8+. Both allow 1. ... Kd5, which gets the King off of the dark squares that White controls but also closer to his N & Q.
There's one light square Black's King wants to avoid: d6, due to Qc8+,skewering the King.
Note that this is only possible if White's first move is 1. Qf8+.
So let's look at that line.
1. Qf8+ Kd5 2. Qd8+ Kc5 3. Qa5+ Kc4. This doesn't look good for White. In fact, why wouldn't Black play 1. ... Kc4 initially?
1. Qa7+ Kd5 2. Qf7+ Qe6 3. c4+ draws the King away from the defense of the Queen.
So Black won't play 2. ... Qe6. Instead, he'll play 2. ... Kd4 and now what?
Since White can't play Bg1+, the King is heading towards safety [e3 then f3].
3. c3+ Nxc3 frees up e4 for the King, a light square.
1. Qf8+ Kd5 2. Qd8+ Kc5 3. Qa5+ Kd4 4. Bg1+ Qxg1 5. Qa7+, skewering the King.
What if Black stuck to the light squares?
1. Qf8+ Kc4 2. Qf7+ Kc5 but now 3. Qa5+ is not possible.
1. Qf8+ Kd4 2. Qd8+ Ke3 3. Qd3+ Kf2 and White has run out of checks.
Wait a minute: 1. Bg1+ is also valid, since 1. ... Qxg1 2. Qa7+, skewering the King.
1. ... Kd5 [1. ... Kc4 2. Qb3#] 2. c4+ Kxc4 [2. ... Ke6 3. Qc8+] 3. Qb3#.
Or 2. ... Ke6 3. Qc8+, again skewering the King.
Yup, that was it.
The key was seeing both skewers: one on the a7-g1 diagonal if Black accepted the Bishop sac offer
and the other on the c8-h3 diagonal if he did not.
And the Qb3 checkmate if he took the pawn.
.
As usual, there will be much discussion [some of it phrased as criticism rather than seeking answers] of why Black "blundered" by playing 1. ... Kd5 instead of 1. ... Nf2 [which clears e4 for the King; if 3. c4+, Black does not play 3. ... Qxc4 due to 4. Qg8+ with yet another skewer].
As usual, the answer is that the puzzle creator chose this particular solution to showcase certain ideas; IMO, it was about the skewer[s].
Had Black played optimally, both skewers would have remained in the notes, unplayed and possibly unseen by many.
By the same token, the checkmate on b3 remained in the notes regardless but that wasn't the highlight of the puzzle.
As regular readers know, I typically trot out the following 2 articles that explain why puzzles do what they do and that any "errors" perceived are features, not bugs.
https://www.chess.com/blog/EnPassantFork/no-the-puzzle-is-not-wrong
As a teacher friend commented, "I don't need to see the parents that always come to Parent-Teacher conferences because their kids invariably are doing well. I need to see the parents that never come."
Same thing here: the people that understand how puzzles are constructed don't need to read the explanations. it's the people that DON'T understand that need to read them and they are the least likely to do so.
Such is the way of the world.