Instead, 81...Qgc5#. I take back what I said about the uselessness of the ...Rb6ch move. Seems it wasn't so useless after all! Sorry.

Here's me, thinking at last you would play 83...Rd6#. Or 83...Qee3#.

Well - you got there in the end! I guess you are developing a fair bit of experience with endings of this type. You seem in less danger of giving away stalemates than formerly - that is an improvement, right there. But check out mating patterns. Here's two ways a pair of queens can checkmate in mid-board: a: b: Note that in both checkmate positions, orientation is immaterial. The way the Queens stand in relation to the enemy King and each other (mutual protection) is what is significant. But never forget this sort of edge of the board mate, neither:

When black made a blunder, you did a good job in exploiting the weakness. Yet, there were a lot of mistakes made by both sides. He could've won back a Queen, and even declared a draw by repetition. In fact, I believe that, at one point, he had the chance for stalemate. The fact is that you missed a lot of opportunities but were still able to force a win which is good. But, you've got to be weary of these things. First, if he didn't blunder the Queen, he'd still have a winning advantage due to being a piece up. And, if he took advantage of the draw by repetition, which Cavyiah did, he would've pulled a swindle in a won position. Lastely, there were opportunities to mate sooner which was overlooked. The idea is to take advantage of opportunities while they're around because they don't last a long time. Missing them could allow the opponent to pull a swindle and draw, or even, win a lost game.