41...Bc6ch was still good, though not checkmate this time. This queen check was just careless, and ought to have met a sharp rejoinder.

?? What's more is that white can get counterplay. How should he proceed, Erika?

42.Bxg5 would have punished Black for her carelessness. Even so Black would still have an easily winning game.

I don't think it was that easy but still winning. Nonetheless, ION is correct, especially since 42.Bxg5 would've gotten back the Queen.

Instead it was White who gets the axe.

Yep.

Simply throws away a perfectly useful bishop - or at least, that's how it turns out. Instead, 43...Qe3ch would have led to a quick mate. Simpler yet: 43...Qd2. Simplest of all: 43...Qg4ch.

Agreed.

Instead 44...Re3, with the idea 45...Qd2ch 46...Re1# was the best plan. The game might have ended like this: 44...Re3 45.Bb5 Qd2ch 46.Kg1 Re1ch 47.Bf1 Rd1 48.Kh1 Rxf1#.

I would have preferred 45...Rd2ch and a mate in 4. This queen check ought to lead to a mate just as quickly, but it is less simple.

No: this is aimless. There were two ways to go here, both leading to 'lawnmower' mates. I like 46...Qe3ch, to get the Q and R off the same file and onto adjacent ones. Whichever way the W King goes, the rook would check next and then the queen finish White off. Mate in three, then, starting with 46...Qe3ch. Instead 46...Rd3ch also was a mate-in-three: 47.Kg4 Qb4ch 48.Kf5 Rd5#.

Remarkable. This is a very sensible move. Probably 47...Qd4ch is simpler, but I do like the creativity behind this.

Very strong would have been 48...Qd4, corralling the King. Threatened with ...Rd5#, White might play 49.Bc6, whereat Black plays 49...h6ch! As 50.Kxh6 Qh4 would be checkmate, White would have to move the king, leading to mate in a couple more moves. This is a fairly hard mate to visualise, though, so a more straightforward, if slower, plan is reasonable. This move, though, merely chases the knig into the open board. You don't want to chase the knig: you want to swallow him up.

Also good was 48...Qg6+ which also does the same thing. But, 48...Qd4 was a quicker approach for the reason that ION mentioned with a quicker mate. Remember: This is like using both Bishops, Knight and Bishop, or even, pawn and Pawn and Queen. The idea is to confine the King to just one corner, and then, one square, where he can't get out. This is a very important aspect to end games

Not a good option. It stands to reason that the lone king should to to the open board for means of escape. On the edge, unless there are prospects of Stalemate, he is more easily trapped. 49.Kg4 was favourite.

Much better was 49...Qg3, threatening 50...Qg5#, and there would have been nothing whatever White could do about it.