Hard Chess Problem

I saw this problem on Wikipedia a couple days ago. It didn't state the solution and I just had to solve it, but I couldn't find the solution. The problem is to create a game where white's 8th move is b7-b8=N# (notice not axb8=N# or cxb8N#). Whatever I tried, I always seemed to come up one move too late. Here is one of my variations:

1. e3 d6 2. b4 Kd7 3. b5 Nc6 4. Qf3 Nd4
5. Qxb7 Ne6 6. Qxa8 Nf6 7. b6 Ne8 8. b7 h6
9. b8=N#

Can any of you solve this?

I played over your game to get an idea and did it in 8!

1. a4 Nf6 2. a5 d6 3. a6 Kd7 4. axb7 Ne8 5. Rxa7 Nc6 6. Rxa8 Nd4 7. Nc3 Ne6 8. b8=N#

Thanks randomchampgamer it was fun trying to solve that!

Nice one! I tried the idea of queening with the a pawn but never saw the idea of Rxa7! and Rxa8. I would always either move the black a pawn to a5, then the black rook to a6 then c6 or capture it with the white bishop or queen. Thanks!

There are many ways to do it in 8.
For example: 1.a4, Na6 2.a5, c5 3. h3 [ mysterious move :-) ], Nc7 4.a6, d6 5. axb7, Kd7 6. Rxa7, Ne8 7.h4, e6 8.b8(N)#

Could 7 be possible?

1c4 d6 2c5 Nd7 3Qb3 Ndf6 4c6 a5 5cxb7 Ra6 6Qxf7+ Kd7 7 b8knight mate

There ya go. :-)