Interesting drawing idea

[John Moore]

From Round 6 of the Qatar Masters

https://lichess.org/broadcast/qatar-mas ... a/UcKyfzPq

Scroll back to the position after White's move 58 and find the draw for Black. Perhaps fairly obvious when you know there's a draw there.

[Christopher Kreuzer]

Black to move and draw:

3k4/3P4/3K4/5p2/B7/3b2P1/8/8 b - - 18 58

It is a standard drawing method in these SAME colour bishop endgames as far as I am aware, but one that you need to be aware of. So a useful instructional position.

(PS. Black, a 2305-rated WGM, failed to find this drawing method and lost, so maybe not so standard or well known.)

[PPS. Other drawing moves may be available? Some of the possible 9 moves may draw, while others definitely lose. Very interesting to work out why.]

[John Moore]

Not an opposite coloured bishop ending, Chris. Although the drawing idea does involve opposing bishops! Thanks for putting the position up.

[Christopher Kreuzer]

Oops!! Thanks, John (have corrected my post above). The Lichess Stockfish struggles to evaluate these positions unless you wait a bit. It looks like there is only one drawing method here though not clear if White had to allow it.

[Should really be using tablebases here!!]

[Tim Spanton]

Black has five drawing moves in the diagrammed position.

It is also a draw with White to move.

Or am I missing the point?

[John Moore]

Sorry Tim. I just saw the f4 idea and thought that it was a neat way to force things.

[Tim Spanton]

Well, yes, it's a nice idea to know, and, as the game shows, clearly there are people who should know it but don't

[Christopher Kreuzer]

Possibly the instructive lesson is how it is possible to lose such positions if you are careless. Admittedly, the White plan of rerouting the bishop to e6 is not hard to see. Black may have been able to set up an easier drawing position earlier, not sure.

1...f4 certainly simplifies the calculations.