# Can you find the key move?

I've created this chess problem for today. it's White to move and their pawns move upward. Can you find the key move? Have fun, and no computers are allowed!

Checkmate In 5 Moves

Addendum 11/6/2021: The below answers have the correct key move, but neither has solved the mate in five yet!

Let's see if black has a good way to prevent

the white king walking to f3 to support the bishop giving mate on g2.
1. Kd3

Black can try

1... Ne6
threatening to put the knight on g5 to prevent the king from entering.

Now, if white takes on e6, the white king does not have enough time to get to f3 as after
2. Bxe6 b5
3. Ke4 b6
4. Kf3
black is in stalemate.

So, it seems that plan doesn't quite work. However, white has another way to deliver mate:

Bring the king over to f4 instead and use the other bishop to deliver mate.
2. Ke4 Ng5+
3. Kf4 Ne6+ (otherwise 4. Bxg4#)
4. Bxe6 b5
5. Bxg4#

• You're first move is correct, but your third one is not, and please give lines for all Black's moves. Commented Jul 10, 2020 at 22:34

I think that this is not

mate in 5

but

mate in 6

With the first move being

1. Kd3

Analyzing all of black options: After this move, black cannot play

1.b5 or 1.Ne8

bacause in these cases

black has no way to stop
2. Ke4 with the idea 3.Kf3 and 4.Bxg2#

One possibility for black is the move

1. Nh5

In this case, white cannot play

2.Ke4 because of 2.Ng3 negates every checkmate in 5 or 6: 3.Kf3 Nxf1 or 3.Nxg3 Kxg3)

but has the option to play

2.Rxh5 forcing mate in 6 after 2. b5 3.e8=Q b4 4.Rb5 Bg3 5.Qh8+ Bh4 6.Rf3#

2.e8=Q which is also mate in 6, forcing 2.Nf4+ (because of 2.b5 3.Qxh5 b4 4. Qxh4#) and forcing white to move the king somewhere, having ideas of checkmating with the queen in 2 on Qxg4# or Qxh4#. However, black does always have the option to give check at least once in all of these lines leading to a variety of forced mates in 6

Looking at the other possible first moves for black:

1.Ne6

is also mate in 6: It leads to 2.Bxe6 b5 3.e8=Q b4 4.d5. Here, black has three options,
4.Nxe5+ 5.Qxe5 Kg4 6.Be6# or
4.Nf6 5.Qe6+ g4 6.Bxg2# or
4.Nh6 5.Qe6+ g4 6.Bxg2# (same as before)

Leaving just

1.Nf5

which is also mate in 6 after
2.Bxf5 e5 3.e8=Q e4 4.Be4 and black having the options
4.Nxe5+ 5.Qxe5 Kg4 6.Qf5# or
black moving the knight to either f6 or h6 which is followed by
5.Qe6+ Ng4 6.Bxg2#

• Your key is correct, but there is indeed a mate in 5. Promotion does take place, but you are using it incorrectly. Commented Jul 23, 2020 at 13:36
• @RewanDemontay You should give the check, though, as you only asked for the key. The rest is a courtesy. Commented Jul 23, 2020 at 15:40
• Um, absolutely not @Weckar E. This is not a correct solution even if the key is correct. You have to find the whole solution-the key is hard, so that's what the main attention was focused on. Commented Jul 23, 2020 at 15:58
• @RewanDemontay Then perhaps the question should be clarified. You ask for the key, you claim this answer gave the correct one. Commented Jul 23, 2020 at 16:00