(293) Two players learn from Tim Krabbé about Salvioli´s rare g4! response to ...g5? Each then encounters it

I gave chess lessons via Skype to a Mancunian girl, Bryony Eccleston. Her mother had requested I teach something about endings so, over the previous couple of lessons, I had been working with her on pawn endings. On April 29th 2020 I was trying to teach her about a rarely encountered tricky breakthrough in a pawn ending of the answering of...g5? with g4! by showing an example of it from a tournament game of 1978 in Kiev between GM Hans Ree and IM Lyubomir Ftacnik.

Since I did not have my signed copy of Ree´s The Human Comedy of Chess in front of me, I had not arranged the pawns on the queenside precisely as they were in the actual game. 

Ftacnik thought he was winning and played 56...g6-g5?? to be stunned by Ree's response of 57 g4!.  All other moves lost for white. But 57 g4! won. 

After an hour´s thought, Ftacnik continued 57...hxg4 58 h5 Ke6 59 Kf2 Kf7 60 Kg3 Kg7 61 Kxg4 Kh6 62 Kf5 Kxh5 63 Kxf6 g4 64 e5 g3 65 e6 g2 66 e7 g1=Q 67 e8=Q+ Kh4 68 Qh8+ Kg3 69 Qg8+ Kg2 70 Qxg1+ Kxg1 71 Ke5 Kf2 72 Kd5 Ke3 73 Kc6 Kd2 74 Kxb6 Kc2 75 Ka5 Kxb2 76 Kxa4 Kc3 77 Kb5 and black resigned.

Afterwards I would send Bryony a follow up e mail directing her to Entry 322 with its listing of all the known such instances of precisely this surprise in a pawn ending (via Entry 392) at one of my favourite websites: Tim Krabbé´s Chess Curiosities - https://timkr.home.xs4all.nl/chess2/diary.htm
In Entry 321 https://timkr.home.xs4all.nl/chess2/diary_17.htm Tim saw what he perhaps took to be the only example of it. But in Entry 322, which he would append in August 2006, he listed seventeen other instances of the breakthrough. And further researches turned up another ten. And then still others!

In the great majority the opportunity to execute the decisive response was overlooked. (Krabbé includes the only occasion when the response was missed... but a subsequent analysis showed it would not have proved decisive!) https://chess.stackexchange.com/questions/12287/does-white-really-have-a-win-in-this-pawn-ending-as-claimed-by-tim-krabb%c3%a9
One example of this pawn break was when fellow Dutchman Gerard Welling, playing white, used it to defeat Vereslav Eingorn - a strong Ukranian Grandmaster - in the German town of Bad Wiessee on November 6 2006.

The position is completely drawn, but after the winning attempt 45...g5?, White did not miss his chance of 46.g4!. After thinking for an hour, Black resigned.

Shortly afterwards, Krabbé posted that Welling told him that he became aware of the trick only because he had read about it a few weeks earlier... at Tim´s site!

PS 19 November: Gerard Welling writes: "Of course I had seen the theme a few weeks ago on your site. During the game I wasn´t completely sure that it was exactly the same, but once you´ve seen a theme, it is generally not so difficult to calculate it. I´d like to add one thing, though. After thinking for a minute, poor Eingorn started mumbling to himself, apparently having calculated all the variations and realising the unpleasant truth. He kept thinking a little longer - I´d say for a minute or 10 - after which he resigned in a gentlemanly manner.

However, the electronic board and lock were not switched off - there was no arbiter around - which has created the impression that Eingorn thought for an hour after g4. That is not true.

Unfortunately, we will never know if I would have seen g4 without prior knowledge."

Welling corrected (Krabbé's) misapprehension that it was after one hour´s thought that Eingorn resigned. Not to forget that Ftacnik really did ponder for an hour after Ree´s response of 57 g3-g4!

When looking up Krabbé's Entries on the Salvioli pawn break for Bryony´s attention, I had actually spotted a misspelling of the word "simple" as "simpe" at Entry 392 and only a few days later, on May 3rd 2020, I e mailed him about it.

At 10:31 A.M. two days later he responded -
Dear Mr Famous Chess Grandmaster,
Sorry about that, always happy with a good corrector.
Cheers,
Tim

On the evening of the day when Krabbé wrote back, Monday May 5th 2020, I played this 3 minute game as Black Vs an opponent styling himself Terminator 1976 at the www.li.chess site -
1 e4 e5 2 c3 Nc6 3 Nf3 Nf6 4 d4 d5 5 exd5 Nxd5 6 Qa4 exd4 7 Nxd4 Bd7 8 Bb5 Nxd4 9 Bxd7+ Qxd7 10 Qxd4 Qe6+ 11 Be3 Nxe3 12 Qxe3 Qxe3+ 13 fxe3 Bc5 14 e4 0-0-0 15 Nd2 Rd3 16 0-0-0 Re8 17 Rhe1 Be3 18 Kc2 Rxd2+ 19 Rxd2 Bxd2 20 Kxd2 Re6 21 Re3 f6 22 Kd3 Kd7 23 Kd4 Ke7 24 Rd3 Rd6+ 25 Ke3 Rxd3+ 26 Kxd3 Kd6 27 g3 Ke5 28 Ke3 c5 29 c4 b6 30 b3 a5 31 a3 h5 ...and my opponent played 32 h3 ...
Had he played 32 h4 instead then my intent was to follow up with what I, at first, thought to be the "winning" reply of 32...g5

Almost immediately I spotted it would have made me one of the less than forty mugs since Salvioli´s study of 1888 to qualify for Krabbé's list by falling for his "simple" winning response of 33 g4!!

And the very first such mug since 2012.

... ... ...

Apropos my opponent´s handle, the film Terminator Six: Dark Fate had been released in 2019.

A scene from it was actually shot some 200 metres from my front door!