Jerome Gambit: Slip?

I will get back to opening and middle game adventures in the Jerome Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.Bxf7+) next post, but for the moment I would like to share another endgame with the caveat, that just as a blitz time control can limit what players see (analytically) in the opening (to the benefit of the Jerome Gambiteer), so too can it limit what players can see when they have fewer pieces on the board (and fewer minutes on the clock).  

As Tartakower said "The mistakes are all there, waiting to be made". It's a shame he never played the Jerome Gambit.

Also, internet chess has a different "feel" from over-the-board chess.

tacticgod - QuangTung2D

10 0 blitz, lichess.org, 2022

White has a Queenside pawn majority. Black has a Kingside pawn majority. Balanced game? No. The g-pawn will serve as a distraction for the White King, while the Black King pursues mischief on the Queenside.

40.b4 

Is White trying to convert his Queenside pawn advantage? Or is this just the best that he has in the position?

Computers have improved their endgame play immensely over the last decade or so. Stockfish 15 sees Black as almost a Queen better.

40...b6

This is a blitz game, and Black quickly opts to balance things on this wing, relying on his advantage on the other wing. 

He could have clarified the situation on the board instead with 40...axb4 41.cxb4 Ke5 and then just let things play out, e.g. 42.Kg4 Kd4 43.b5 cxb5 44.axb5 Kxd3 45.Kxg5 Kc4 46.Kf4 Kxb5 47.Ke3 Kb4 48.Kd2 Kb3 49.Kc1 b5 50.Kb1 b4. One extra pawn is enough 

41.bxa5 bxa5

Things have changed: the position is equal. The Kings will take over.

42.Kf3 c5 43.Kg3 g4 44.d4 cxd4 45.cxd4 Ke4 46.d5 

After 46...Kxd5 47.Kxg4 Ke4 Black's King will mark White's and keep it from the pawns, ensuring the draw. It is not the that win he had a few moves ago, but he will have salvaged a half point.

46...Kd4 

This can only be a mouse slip. (I suppose such things happen in over-the-board chess - Ooops, I dropped the piece - but they have to occur less often.)

Now White's pawn can run away and promote to a Queen. 

47.Kxg4

Mental inertia. Perhaps White has been focusing on equalizing the game so much that he misses the winning 47.d6.

White returns the game to even.

47...Kxd5 48.Kf4 Kc4 49.Ke4 Kb4 50.Kd3 Kxa4 51.Kc2 Ka3 52.Kb1 Kb3 53.Ka1 a4 54.Kb1 a3 55.Ka1 a2 drawn by stalemate