Resigning In A Won Position

I PLAYED at Bradford over the weekend, hoping to repeat last year's feat of winning the U171 tournament.
Instead, I had one of my worst congresses ever, despite facing five players graded 117-147, ie considerably lower than my 169.
I had losing positions in every game, but somehow managed to scrape together a 50 percent score.
I was much helped in this by my round-three opponent resigning in a won position.
Here is the game after White's 50th move:

Spanton (169) - Dennis J Wright (141), Bradford U171, 2017

Seeing he was about to lose his pinned bishop, my opponent played 50...Rxe2, desperately hoping I would fall for 51.Kxe2 Qa6+, when Black picks up White's bishop and has an attack against the exposed White king.
But I was ready for this and so played 51.Qxe2, prompting DW to immediately resign.
It was only later that evening, putting the game into my database, that I realised - thanks to analysis engines - that Black, not White, is winning after the simple 51...Qxf5+.
True, White can save his bishop with 52.Bf2, but the engines have Black winning easily with 52...Bb6. Materially, Black has only a pawn for the exchange, but there is much more to come thanks to the exposed nature of White's king.
On a brighter note, the congress, held upstairs at Bradford Latvian club, featured good playing conditions and, an increasing rarity these days, a well-stocked bookstall.

Players gathering before round four on Sunday morning

New Team, Old Tim

MY first game for my new club had a familiar feel to it - I get a slight edge out of the opening against a higher-graded opponent; he runs short of time in the middlegame and offers a draw; I over-rate my position and play on; I too get short of time and the blunders follow.
It's late and I'm off to Bradford tomorrow morning a for a weekend congress, but I hope to post more about the game once I've had a chance to look at it in more detail.
For the moment, here is the position after Black's 20th move, at the point where he offered a draw.

Spanton (169) - Angus French (183), Central London League

Incidentally, we (Battersea) lost the match (against Pimlico Knights) 4-1, and I now have a lifetime score against AF of +2=0-3.

A Position That Baffles Computers

EVERYONE knows analysis engines are very strong these days, but there are still positions they find hard to evaluate correctly.
Most such positions occur when there are lots of men still on the board, but in my most recent tournament, the Devon County Congress at the Livermead House Hotel earlier this month, the following example arose after White's 60th move.

Spanton (169) - Daniel Gibbs (153), Rowena Bruce Challengers 2017

The game continued routinely: 60...Nd7 61.Kd4 Kxh6 62.Kxc4 Kg6 63.Kd5 Kf6 64.a6 Nb6+ 65.Kd4 Nc8 66.Nb5 Ke7 67.a7 Nb6 68.Nc7 Kd7 69.a8Q Nxa8 70.Nxa8 Kc6 1-0.
But the next day DG told me he actually had a draw, and this does seem to be the case - but you have to give analysis engines plenty of time to find it.
The key line runs: 60...c3 61.a6 Nxe4! 62.a7 c2 63.Kxe4 (63.a8Q c1Q+ doesn't change the outcome) c1Q 64.a8Q Qh1+ with a trivial draw.
So it seems 60...Nd7 should have a question mark (under the John Nunn endgame convention).
Analysis engines eventually realise White is not winning in the diagram position (although many continue to believe White is much better), but it certainly baffles them at first.