If Kxb2 Rb8+ Bb5 Rxb5 Qxb5 Qxb5 + which must be won for black in the long run.

White has gained material but the game is lost. Black threatens Rb1+ Rxb1, Qc3+ etc. This check allows white the tempo he needs to interrupt that sequence but as usual with my tactics there is a big flaw...

Initially, when I played Qxb7, I had intended Bc4 but realized now that when I play Rd1xb1 the protection the rook affords to the square d4 is removed so as to allow Qd4+ and the same finish.

So black offers the rook as a decoy for my queen away from protecting c3 and d4.

If Kxa2 then Qa5+ Qa4 Qxa4 mate.

Black lands the dreaded check...

Forced.

Crashed and burned. So, what have we learned? Well, nothing I didn't know already really but it does no harm to reinforce good lessons, because that is going to happen anyway until they are properly taken to heart. In summary. When the play leaves my theoretical knowledge, whether memorized or looking it up, consider the position carefully and don't play the first superficial plan that comes into my head. Make sure that the projected play for both sides does not leave me worse off than the current position, here in the moves 14-18. Do not succumb to the temptation to play a move that is obviously bad (Qxb7), just because you don't see the opponent's winning tactic until a move or two into a sequence you can't escape. If the hairs go up on the back of the neck do not ignore it. The tactics missed when Qxb7 was played were Qc3+ (or Qd4+) because the b2 pawn was protecting that square even though Rxb2 was considered. Later when Bc4 was intended the decoy of the Rd1-b1 was also seen too late. On this site I have not been inclined to move pieces during analysis so as to keep conditions as close to OTB as possible. Perhaps it is time to start!