Lessons From Northumbria VIII

IN round eight of the Northumbria Challengers (U2000) I blundered my queen in the following position:

I played 40...Qc1+?? in Robert A Dean (1724 Fide/1861 ECF) - Spanton (1808 Fide/1998 ECF)

Putting the blunder to one side, the interesting thing about this queen-and-pawn ending is that it is probably drawn, despite White having a farside pawn-majority.

I want to show, using mainly analysis by the engines Stockfish14 and Komodo12.1.1, why this is so.

First, a couple of general points.

1. A passed pawn in a queen-and-pawn ending is often decisive. In many cases the player with a passed pawn will beat an opponent who is a pawn up but does not have a passer.

2. A key defensive resource in queen-and-pawn endings is to threaten perpetual check.

Anyway, here is more-or-less how the game should have gone.

40...a5!

Using the second point above as 41.Qxa5? allows a simple draw starting with 41...Qe3+.

41.Qc3 Qf5 42.g4!?

Not 42.b4? Qb1+ etc.

42...Qd5 43.Kf2 h5 44.gxh5 Qxh5 45.Ke1

The king is trying to head for shelter on the queenside.

45...Qd5 46.Ke2 g6 47.Qe3 Qd8 48.Qe5 Qb6 49.Qe7+ Kg8 50.Qe3 Qd6 51.Qd3 Qe5+ 52.Kd2 Qb2+ 53.Kd1 Kh7

Very little of the above is forced, but it seems clear White cannot make progress against reasonable defending.