Tuesday, April 27, 2021

Beating max level Stockfish with the Jerome Gambit (Part 2)

 


[continued from previous post]


razornfs - lichess AI level 8

15 10 standard, lichess.org, 2021


31.Rag1 Kf7 32.Rg5 Rae8 33.Ke2 Nf6 

Stockfish 13 criticizes this move, and gives an alternative line of play where Black ultimately forces a draw by repetition.

34.Rc1 Rc8 35.Rc6 Rgd8 


Again, my computer - that did not suffer from the time contraints of the ones playing the game - preferred a line where White advances his e-pawn, and everything gets blown up, leading to equal play where Black will likely take advantage of the open position of the White King to check with his Rook, looking for a draw by repetition: 35...Ke8 36.e5 Nxd5 37.exd6 Nb4 38.Rxc7 Rxc7 39.dxc7 Kf7 40.f5 Rc8 41.Rxg6 Rxc7 42.Rxb6 Rc2+ 43.Kf3 Nxd3 44.Rd6 Nb2 45.Rd4 Rc3 46.Kf4 Ra3 47.b6 Rb3 48.Rd7+ Ke8 49.Ra7 Rxb6 50.Rxa5 Rb4+ 51.Kg5 

This is, of course, way over my head. 

36.Kf3 Ng4 37.e5 Rg8 38.e4 

Probably 39.d4 followed by 39.e4 was better. Those pawns!

38...dxe5 39. fxe5 Ke7 


An outline of the drama to come appears.

40.Ke2 Kd7 41.e6+ Kd8 42.d4 Ke7 43.e5 Rg7 44.d6+Kxe6 45.Kd3 Nf2+ 

The lichess computer labels this a mistake; 45...Kd7 was best. 

White wants to advance and promote one of his pawns, and an active King will help. Exchanging a pair of Rooks will cut down on Black's defense / counterattack options. Black will look to check towards a draw, if need be.

46.Kc4 Kd7 47.dxc7 Rxc7 48.d5 Ne4 49.Rg2 Rg8 50.Kd4 Nc5 51.Rf2 Kd8 52.d6 Rb7 53.Kd5 g5

Seeking counterplay, but White's center pawns are too powerful. They will force concessions.

54.hxg5 Nd3 55.Rf6 Nxe5 

Desperation - if computers could feel desperation.

56.Kxe5 Rxg5+ 57.Ke6 Rg8 58.Rh6 Rbg7 59.Rxb6 Kc8 60.Rxh5 Rg6+ 


When the checks stop, the game will be over.

61.Kd5 Rg2 62.Ra6 Kb7 63.Rh7+ R8g7 64.Rxg7+ Rxg7 65.Rxa5 Rg5+ 66.Ke6 Rg6+ 67.Ke7 Rg7+ 68.Kf6 Rg2 69.Ra6 Kc8 70.Ra7 Kd8 71.a5 Rf2+ 72.Ke5 Re2+ 73.Kd4 Rd2+ 74. Kc5 Rc2+ 75.Kb6

75...Rd2 76.a6 Kc8 77.Rc7+ Kd8 78.a7 Rxd6+ 79.Kb7 Rd7 80.a8=Q+ Ke7 81.Qf8+ Ke6 82.Qe8+ Kd5 83.Rxd7+ Kc4 84.Qe3 Kb4 85.Kb6 Kc4 86.Rd4 checkmate

Never underestimate the power of the "Jerome pawns".


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