Rook and Bishop vs Rook and Pawn

I saw an interesting position with Rook and Bishop vs Rook and Pawn.  It came from a chess composition by Kasparian that was flawed (he suggested ...Kg6? instead of ...Kh5! - see 2nd diagram).  He found a draw, but with best play, it is a win for Black.  I called up several engines and gave it 2 minutes to solve this position.  The winning move is 1...Ra7, with mate in 29 or 1...Rg7+ with mate in 31.  All other moves for Black draw.  Critter found a mate with Ra7, but in 52 moves.  Crafty thought it was a draw and liked ...Re7.  Firebird thought it was a draw and liked Rc7.  Fritz 10 saw that Ra7 was winning, but thought Rg7 was a draw.  Fruit thought Rg7 was a draw.  Hiarcs liked Rc7, but that draws.  Houdini liked Ra7, but thought it drew.  Naum liked Rc7, which draws.  Rybka 3 thought Rg7 drew.  Shredder found Ra7, but thought Rc7 and Re7 also won.  Stockfish found Ra7 right away, but thought Rg7 drew.  Zappa thought Rg7 drew.  Arasem thought Rh1 was winning.  Ares liked Rh1, but said the position was a draw.  Aristach found Ra7 and Rg7 as winning, but also Re7.  Booot liked Rh4, but drawn.  Comet thought that Rh4 and Rh6 was winning.  Cyrano liked Rh1, but evaluated the position as drawn.  Daydreamer thought Ra7 was a draw.  Deep Frenzee thought that Rc7 and Re7 won.  ECE liked Rh4, but drawn.  Gibbon thought Rh4 was winning.  Glass thought Rc7 was winning.  Glauring thought that Rc7, Re7, Ra7, and Rg7 all won.  Hamster saw Ra7 as winning wight away, but also thought Re7 won.  Homer thought that Rg7 won but that Ra7 drew.  List liked Rh1, but a draw.  Little Thought thought that Re7 won.  Movie found Ra7 right away.  N2 thought that Ra7 and Rc7 won.  Patzer said that Ra7 and Rc7 were a draw.  Pawny found Rg7 as a win.  Pharaon thought that Rg7 was a draw.  Philou liked Rc7, but a draw.  Pro Deo thought that Ra7 and Rg7 were drawn.  RobboLito liked Ra7, but evaluated it as a draw.  Ruffian thought that Ra7 and Rc7 won.  Simplex thought that Rh4 would win.  SlowChess thought that Re7 wins.  Spike thought that Ra7 drew.  Sungorus thought that Re7 wins.  Tao thought that Rc7 wins.  The Baron liked Re7, but judged the position a draw.  Toga thought that Ra7 and Rg7 drew.  Tornado thought that Ra7, Rg7, and Rc7 all won.  Twisted Logic thought that Ra7 drew.  Ufim liked Re7, but drawn.  Umko saw Ra7 as a draw.  Wildcat wanted to play Kxe6 and draw.  bright thought that Rg7 drew.  Spark thought that Ra7 and Re7 drew.  Again, all these engines had at most 2 minutes to evalute the position.   The Nalimov tablebase was used to evaluate the position with 6 pieces.

Nice article. Hard to mantain focus to think that about 30 moves later it could be mate.

Great, Thanks