# Deja Vu (4)

Neo: Whoa. Déjà vu.
Trinity: What did you just say?
Neo: Nothing. Just had a little déjà vu.
The Matrix, 1999

White to move and mate in 4
Hint: the third move is a check

My friend Nick had the above posted online. It looked very familiar. I could bet I have seen this puzzle before. At the beginning the hint made it look trivial. How complicated can a mate in 4 puzzle with such a hint be? Then I started to look for the possible solution and it did not feel trivial anymore. How can this be? I had the general idea in my mind but could not work it out together with the hint. Give it a try and see what you can do.

Moving the bishop or the king made no sense. White cannot drop the rook and still hope to checkmate. The move 1. Ne7+ made little sense as well, so the rook check was quite obvious. Now I was trying to figure out the 3rd move being with check. I remembered vaguely that I needed to move the king to g5 in order to defend the knight. The hint meant that I needed to move the king right now. Still that would not work because of 2.. Nh7+ and there is no mate in 4 anymore.

At this point the only logical idea was to deflect the knight to e8 with 2. Be8+. However if I did that, the hint is not working. It is impossible to give another check at move 3 without dropping a piece. What a heck is going on here? Could you figure it out? I took a break from it. This is not easy to do as the puzzle is still “living rent free” in your mind. I don’t deserve any credit for this figure of speech. I heard it in a movie and it stayed with me. Nevertheless do that when you get stuck in any situation.

Later on I came back to the puzzle and figured it out right away. I found the mate in 4 and was certain the hint was wrong. Had another look at the original posting and all made perfect sense. The hint actually read:
Third move is not a check
You might not believe me but this is what happened. The mind can play tricks on you by giving you a signal this is something you’ve seen before. You look at it and see only what you want to see. Instead of figuring it out in a few seconds, it made me work for it. Watch out for the black cat passing by in the doorway!

Eugen Demian