The content of a game should be a search for truth, and victory a demonstration of its rightness.
Vasily Smyslov
Back in 1997 in a simul put on by the then strongest local player, a high school student named Nate Fewel, I forced the exchange of rooks to go into a king and pawn endgame. I won this ending against Nate that day, and against Fritz 9 this morning.
Black to move
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Against Nate, the game continued
34...Rd2+ 35.Rxd2 cxd2 36.Ke2 Kf8 37.Kxd2 Ke7 38.Kc3 Kd6 39.b4 g5 40.fxg5 hxg5White to move
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Here, Nate played
41.bxa5, and his king became immobile defending against the onslaught of my pawns rolling down the center; my king was free to mop up the queenside.
Fritz 9 played differently: After
34...Rd2+ 35.Rxd2 cxd2 36.Ke2 Kf8, Fritz played 37.b4. After 37...Ke7, we reached this position.
White to move
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Fritz played 38.bxa5 and had the same problems as Nate.
After beating Fritz, I tried the position anew, this time against Hiarcs 12, which played 38.b5!.
The engine continued to evaluate the position as winning for Black, but I could not find the way to promote a pawn soon enough to prevent White's equalizing promotion of the b-pawn. I tried using the suggest a move feature with the same results. Black seems to have a clear advantage, but good moves by both sides appear to lead to a drawn queen and pawns versus queen and pawns endgame.
In 1997, postgame analysis with Chessmaster 3000 confirmed that 34...Rd2+ is a winning move. Play against Fritz 9 seems to confirm this judgement; but, a stronger engine introduced doubts. What is the truth?