23. d7+ looks strong to me:
23. ... Kb7
24. d8=N+ !
or
23. ... Kb8
24. d8=Q+
Well, if you want a theoretical quicker mate, you have to look at how fast the mate would have resulted in this case. Let's see...
27. ... Bb8
28. Rxb8+ Ka7
29. Be3#
or
27. ... Kxa8
28. c8=Q+ Bb8
29. Nc7+ Ka7
30. Qa6#
... so far, I can't find anything faster. I've been toying with 25. Rd8+ Kb7 26. Rxa8 but black can interpose a piece at b8 and cause problems with pawn promotion. So you probably made the optimal choices when you could.
There's nothing in the 23. d7+ Kb7 24. d8=N+ line that shows any promise with respect to making a cohesive mating net. Black can just take the new piece and eventually escape wtih his king to a5 or keep blocking w/ pieces. For example, 24. ... Rxd8 25. Nxd8+ Kb8 doesn't give white much of an attack. Remember that the bishop on e4 prevents Rb1+.I know this is not relevant to a quicker mate, but:
10. O-O
Seems better than losing your queen with:
10. Qe2
In this manner the queen would most likely do:
10. ... Qxa4
This way you'd not swap queens but only lose a bishop.
Maybe I'm wrong, thought I'd put that out there... And again, sorry this doesn't explain a quicker mate.
unHOLYdoNUTS:
In my line, after 25. ... Kb8, White has 26. Nxf7, having won 2 rooks at the cost of a pawn. While it isn't a mating attack, the resulting 2 rook disadvantage is significant, and most players would resign at that point.
I know this is not relevant to a quicker mate, but:
10. O-O
Seems better than losing your queen with:
10. Qe2
In this manner the queen would most likely do:
10. ... Qxa4
This way you'd not swap queens but only lose a bishop.
Maybe I'm wrong, thought I'd put that out there... And again, sorry this doesn't explain a quicker mate.
I know this is not relevant to a quicker mate, but:
10. O-O
Seems better than losing your queen with:
10. Qe2
In this manner the queen would most likely do:
10. ... Qxa4
This way you'd not swap queens but only lose a bishop.
Maybe I'm wrong, thought I'd put that out there... And again, sorry this doesn't explain a quicker mate.
10. 0-0 is not possible; you cannot castle while in check.
I've already seen a couple errors by me (white), at a first glance. Im curious as to whether or not anyone else can find a quicker line to mate, considering this game had some great tactical positions to work with!