Can you find a stronger move than a (modern) engine does?

Hello folks,

I had this FEN-Position in one of my games:
r1r3k1/p4ppp/1p2p3/n2p2Pn/3B2q1/8/PP1N3P/4RR1K b - - 2 23

I checked this particular position on my local engine (Stockfish 9) to find the best move for black. I let the computer calculate on this position for exactly 5 minutes to see what it suggests. The suggested move is Qxd4 with an evaluation of roughly -50. As you can see here: image.ibb.co/frkjzn/evaluation.jpg

But actually there is a much stronger move that the engine didn't find even after 5 minutes of pure computer calculation power. Can YOU find it?



SPOILER ALERT:

The stronger move is: Ng3+
Directly after playing this move, the engine doesn't like it at all. (Evaluation says only -23 on depth 21, which is pretty weak compared to the -50 for Qxd4).
But after 60 seconds of calculation on this move the engine goes completely insane, showing an evaluation of -300 and even more.
After only 3 minutes, the engine finally announces forced check mate in 18 moves (if defended perfectly by white):
preview.ibb.co/dekHKn/analysis2.jpg

Both moves win, so why should one be called stronger than the other?

The faster you win the stronger the move... Easy logic.

I would like to see more detail on how this is the fastest route to victory. 24.Kg1 from White seems like a blunder to me. 24.Kg2 seems better or even 24.hxg3 (where's the attack?). Make no mistake, all of these lines win for Black. I just don't see how it justifies not playing the simple 24.Qxd4+, unless of course Black just wants to make the victory look all pretty.

If you play 24. Kg2 or 24. Kg1, the variation is exactly the same:
24.... Nxf1+ 25.Kxf1 Rc2 {I don't care about your hanging bishop, you're in trouble anyway} 26.Re2 Nc4 27.g6 Nxd2+ 28.Ke1 Qxd4 29.gxh7+ Kxh7 30.Kd1 Nb1+ 31.Kxc2 Rc8+ 32.Kxb1 Dd1#

If you take the knight on g3, you win all of white's pieces (except the rooks of course) with check, starting with
24. ... Qh3+ 25. Kg1 Qxg3+ 26. Kh1 Qh4+ 27. Kg2 Qxg5+ and so on....

Simplifying the position a lot, which makes it much easier for the engine to find a forced mate.