Checkmate all the kings #3

Question

Following the rules created by Lord of dark in this puzzle, and used here also, the idea is to find the minimum number of consecutive white moves to checkmate all the black kings (in this case 12). You cannot make a move that would put white in check.

Here's an interactive board.

RULES

• You are playing as White and you can make as many moves as you want before Black's turn.
• During your moves you can take any black piece except kings.
• During your moves your king can not be in check position.
• At the end of your turn all the black kings must be check mate : if Black can make one move that ends with one king being safe, you don't win. Note that this one move can't be a king moving to a threatened position.
• One piece can be used in multiple checkmates (you don't have to take all the king, just to checkmate them)

Answer 1

Thirteen moves:

1. d x c8

2. c x d8

3. h x g8

4. g x h8

5. Q x b6

6. Qc x c5

7. Q x c4

8. Q x c1

9. Qc x b2

10. Qg2

11. Qg x b7

12. Qh3

13. Qh x b3

Here's an animated GIF of the solution. (Assume all promoted pawns become queens, since I couldn't figure out how to convert them automatically using this particular chess software.)

Answer 2

I've done it in 18 moves, one pawn at a time:

Solution:

Moves:

H pawn:

1. hxg8=N, Nf6, Ne4, Nc3

G pawn:

5. gxf8, Ne6, Nd4, Nc2

C pawn:

9. cxd8, Nc6

F pawn:

11. Fxe8, Nf6, Nfd5

E pawn:

14. e8=N, Nc7

D pawn:

16. d8=N, Nde6, Ned4

Answer 3

Found it in 11, probably the optimal.

C pawn takes D8 and B6 - 2 moves

.

D pawn takes C8 and B7 - 2 moves

.

E pawn takes F8 and C5. Then waits a bit. - 2 moves

.

F pawn takes G1, C4 and B3. - 3 moves

.

E pawn now takes C1 and B2. - 2 moves