The backward passer

Lyudmil Tsvetkov · Post by **Lyudmil Tsvetkov** » Mon Jan 21, 2013 7:54 am

[d]6k1/3r1p2/3P2p1/2Q2bP1/5P2/6K1/8/8 w 0 1

This is a very simple position which humans instantly recognize as drawn.
Are there any engines that would instantly evaluate the position as drawn?

My take on that (just to spur on the discussion): White can try 4 different methods to attempt winning, and all 4 of them are unsuccessful, so that the draw could be recognized straight away:
- try advancing the d6 passer, and that is impossible, because the passer is backward, it can not advance without being lost, as the square immediately in front of it is controlled by 2 pieces of lower power than the white piece (the queen) that could support its advance; therefore, it is impossible for the passer to advance
- attempt bringing in the king to try mating the black king, and that is impossible, because there is a continuous line of squares (fortress) around the black king through which the white king can not pass: the line would be, although irregular in shape, a7-d7-d6-f6-f5-h5; squares from a7 through d7 are controlled by the rook, on d6 is the fixed (blocked passer), e6 is controlled by the bishop, f5 and h5 are controlled by the g6 pawn, on g5 there is a fixed pawn, and the black king itself is always able to control the f6 square (if the white king attempts to penetrate via e5); therefore, this is a fortress through which there is no penetration
- attempt moving some pawns that are still not blocked; the only one such pawn would be f4, but it is backward-fated (partially, as one of the pawns that should control the square in front of it is actually a piece of lower power), and therefore, it can not advance without being lost.
- attempt zugzwanging black, which seems to be impossible, as the black bishop can freely go from f5 to e6 and back without compromising the position in the least

The logical conclusion should be: the position is a straightforward draw.

Are there any engines recognizing this?

Best, Lyudmil

PS. Again, I am posting this with best intentions in mind. By recognizing some drawing patterns early on, an engine can opt for a less promising variation, but that actually offers better chances of winning, instead of a variation that is huge in score, but leading to the above position, actually drawn.