Move 16
 

I think we must take 16. .. Bxb5 so the Ra8 can protect the a5 pawn.

After 17. axb5 .. Rxb5 would they then move 18. R(f)-b1 ?

Even with some moves forced the lines can be quite deep in this position.
After 16. .. Bxb5 17. axb5 Rxb5
the following are pretty much forced.
18. Rxa5 Rbxa5 19. Nxa5 Rxa5 20. Bxa5 Qxa5
18. Rxa5 Rbxa5 19. Bxa5 Rxa5 20. Nxa5 Qxa5
18. Bxa5 Rbxa5 19. Rxa5 Rxa5 20. Nxa5 Qxa5
18. Nxa5 Rbxa5 19. Rxa5 Rxa5 20. Bxa5 Qxa5
18. Bxa5 Rbxa5 19. Nxa5 Rxa5 20. several options
18. Nxa5 Rbxa5 19. Bxa5 Rxa5 20. same as above
It is the other moves for white at move 18 that need to be examined.

Yes, I agree with 16...Bxb5 17.axb5 Rxb5 and think it looks good for us.

If White captures on a5 as in WMH's lines they just lose two pieces for a rook. 18.Bc3 might be their best move, protecting b2 and neutralising our pressure on the long diagonal. I think we'll then have to move our rook off b5 out of the way of their e2 bishop (better than 18...Bxc3 19.bxc3 removing their b pawn from attack down the b file), and we return the pawn (our a pawn). But we retain pressure down the b file and their b pawn remains vulnerable, whether they exchange bishops on g7 or not.

My choice at the moment is certainly 16...Bxb5.

On further consideration it seems to me that after 16...Bxb5 17.axb5 Rxb5 18.Bc3 perhaps we should play 18...Bxc3 after all to neutralise their threats, because if instead 18...Rb7 or 18...Rbb8 we are in some difficulty with attacks on rook and forking threats when they reply 19.Nxa5.

But after 16...Bxb5 17.axb5 Rxb5 18.Bc3 Bxc3 19.bxc3 (not 19...Nxd6? 20.Rxb2) we have 19...Qb8! and now they cannot discover the attack on b5 by moving their knight because we would again reply 20...Rb2. After 19...Qb8 they will have to do a bit more work to regain the pawn (our a pawn) and we retain our initiative on the queenside. Does this line look okay to you both, or have I made a mistake?

Here's a different 18th move they might play. It looks complicated.

16...Bxb5 17.axb5 Rxb5 [B]18.e5[/B] Rbb8 19.Nxa5 (19.e6 or 19.exd6 just re-open the diagonal and allow ...Rxb2 again if their knight moves) and now I don't think 19...Bxe5 20.Nc6 Rxb2 works because of 21.Qxb2! and we seem to be a rook down in all lines. Nor does 19...Nxe5 (protecting c6) 20.f4! seem to be any good. Can anyone see how we can handle 18.e5 ?

Getting the feeling at the moment that we should be playing 16...Bxb5 but then delaying the capture of the pawn on b5. Something like 16...Bxb5 17.axb5 Nc7 18.Bxa5 Qc8. I think we are only temporarily a pawn down. If 19.b6 Na6 we should soon round up that pawn on b6.

Unless you two can see how we handle their move 18.e5 in the line in the previous post? That now looks bad to me.

16...Bxb5 17.axb5 Nc7 18.Nxa5 then Nc6

So far the 16...Bxb5 17.axb5 Rxb5 18.e5 I'm still looking at it.

[QUOTE=WMHalsdorf;401909]16...Bxb5 17.axb5 Nc7 18.Nxa5 then Nc6[/QUOTE]
I think after 16...Bxb5 17.axb5 Nc7 18.Nxa5 we can do well with 18...Nxb5 because if 19.Nc6 Nd4 20.Q-any Nxc6.
And I don't think we should be afraid of 19.Bxb5 Rxb5 20.Nc6 Qe8 21.Nxe7+ Kh8 (or 21.Rxa8 Qxa8 22.Nxe7+ Kh8) because we'll play ...Rxb2 next after they've safeguarded their threatened knight.

[QUOTE=Brian-E;401935]I think after 16...Bxb5 17.axb5 Nc7 18.Nxa5 we can do well with 18...Nxb5 because if 19.Nc6 Nd4 20.Q-any Nxc6.
And I don't think we should be afraid of 19.Bxb5 Rxb5 20.Nc6 Qe8 21.Nxe7+ Kh8 (or 21.Rxa8 Qxa8 22.Nxe7+ Kh8) because we'll play ...Rxb2 next after they've safeguarded their threatened knight.[/QUOTE]

Since we have plenty of time left and their move was not entirely expected I know I would like to look deeper into this line since it appears that we could end up even in material with a passed pawn or ahead in material.

[QUOTE=WMHalsdorf;401975]Since we have plenty of time left and their move was not entirely expected I know I would like to look deeper into this line since it appears that we could end up even in material with a passed pawn or ahead in material.[/QUOTE]
Yes, though I think they would play 18.Bxa5 instead.

We have just over 48 hours before we must make the move. If you two have some further suggestions, please post them while we still have time to discuss them.