2024/04/03 DPA: "Interference Clearance, What's Your Guidance?"
White to move.
White is down enough material that simply winning a Rook, for example, probably won't be decisive. So this might be about checkmate.
White would like to play Qg7# but the b Rook is preventing that. And don't forget about the remote Bishop on a2 guarding f7.
1. Bd7 blocks the b Rook from guarding g7 AND frees up e8 for Qe8#, while simultaneously blocking the d Rook from reaching the back rank.
1. ... Rd2+ 2. Kh3 Be6+ 3. Qxe6+ Kh8/h8 4. Qe8#
The puzzle solution chose immediate death with 1. ... Rbxd7 2. Qe8#. Not sure why, as the line above is only 2 moves longer and doesn't dilute the puzzle. In fact, White could err with 3. Bxe6, blocking his own Queen from e8.
Bd7 is called an Interference maneuver in that it blocks the opponent's defenses by preventing them from protecting certain squares or communicating with each other. And it is also a Clearance tactic because it opens the way for the Queen to reach e8.
It was a classic Zombie scenario: the opponent is in a room with 2 doors at either end but neither have locks. He can bar one door but not both - the Zombies are getting in one way [g7] or another [e8].
This puzzle might have been difficult if one follows the CCT/A [Checks, Captures, Threats/Attacks] model because there were no good checks or captures and the Bd7 move is quiet move that is nonetheless venemous.
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If you made it this far, the title was inspired by the Schoolhouse Rock episode "Conjunction Junction, What's Your Function?":