Sunday, 3 June 2018

RIP Valeri Yandemirov

I've just found out via that Valeri Yandemirov passed away last year at the age of 55:

Not a household name, but he was a grandmaster with a peak rating of 2545 in 1998, and he was rated in the 2500s for most of the "noughties" as well.

The main reason why the name sticks out for me is that he was a big practitioner of two daring and sacrificial lines in the Ruy Lopez Modern Steinitz Defence: the Siesta Variation (1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6 5.c3 f5) and the line 5.0-0 Bg4 6.h3 h5, which some have started naming after him (notably Timothy Taylor in his book Slay the Spanish).  The idea most commonly associated with Yandemirov was, after 7.d4 b5 8.Bb3 Nxd4 9.hxg4, to play 9...Nxb3 (instead of 9...hxg4 10.Ng5 Nh6, which has been shown to be insufficient for Black) 10.axb3 hxg4 11.Ng5 Qd7.

 Black is currently a piece down but can generally regain the piece with ...f6 and ...fxg5 since the knight on g5 has no retreat square.  The main idea is however to play ...Qf7 and ...Qh5 and try to mate White down the h-file.  On the other hand this line is still theoretically dodgy because in the meantime White can smash Black on the queenside.  The line was dealt quite a heavy blow in the game Gashimov-Grischuk, Baku 2008:

Nowadays, while 4...d6 has seen some popularity at the highest levels, GMs such as Shakhriyar Mamedyarov and Nigel Short have tended to prefer 5...Bd7 over 5...Bg4, but the 5...Bg4 line has still seen a few recent GM outings, particularly in the hands of Laurent Fressinet:

Aseev-Yandemirov, Krasnoyarsk 2003 was arguably the greatest advert for his pet line:

I have tried these lines out myself from time to time since 2009 and currently have an online game that has reached the position after 6.h3 h5.  I tend to think that if it can work at GM level it must be good enough for mere mortals, even though it may be of marginal theoretical soundness.

Monday, 16 April 2018

An intriguing transposition from the Albin Counter-Gambit into the Göring Gambit Declined

I've probably mentioned the transposition from the Chigorin Defence before (it was also mentioned about a year and a half ago over at 200 Open Games).  Recently I managed to get it in one of my own online games, fittingly, in a match between "The Gambit Players" and "Philippine C", and it actually started out as an Albin Counter-Gambit: 1.d4 d5 2.c4 e5, and White replied with the tame 3.e3.  After 3...Nc6 4.cxd5 Qxd5 we were into a Chigorin, and after 5.Nc3 Bb4 6.Nf3 exd4 7.exd4 we were into a Göring/Danish Gambit Declined.

Capablanca's line with 7...Bg4 8.Be2 (8.Be3!? - Mark Nieuweboer) 8...Bxf3 9.Bxf3 Qc4 gets pretty sterile if White knows what he/she is doing, so I was tempted to duck out with the sensible 8...Nf6, but as I was playing a slightly higher-rated player with Black I thought I would test my opponent out in the Capablanca Variation.  It worked, for after 7...Bg4 8.Be2 Bxf3 9.Bxf3 Qc4 10.Bd2?! 0-0-0 11.Qe2?! Qxe2+ 12.Bxe2 Nxd4 I was already a pawn up and managed to win with the extra pawn after a long struggle.

In the meantime I finally had an outing in the line that I had corresponded with Gary Lane about over at Opening Lanes (  1.e4 e5 2.d4 exd4 3.Nf3 Nc6 4.c3 d5 5.Bd3!? dxe4 6.Bxe4 Nf6 7.Bxc6+ bxc6 8.0-0 (which both of us suggested independently of each other).  I got some pressure in the IQP middlegame that ensued but did not make the most of it and ended up with a draw, but my opponent came close to losing on time.

Also I'm currently working on what will probably end up as a book-sized pdf article on the "open gambits" with an early d2-d4 (including the Italian and Max Lange gambits as well as the Danish, Göring, Scotch and Urusov) so that all the various transpositions will be handled in the one pdf file, and there will be links to replayable annotated examples in the text.  It's an ambitious project so it may well take me several months, but it would be satisfying to pull it off.

Wednesday, 24 January 2018

Trying out Stockfish 8

Having used a combination of old versions of Fritz and Rybka to error-check my chess analysis for years, I decided to give Stockfish 8 a go.  Ironically, this was prompted by Stockfish's much-publicised losses against Google's AlphaZero.  Yes, even bad publicity can be good.

I'm already finding that Stockfish sometimes disagrees with what Fritz and Rybka had to say on particular opening lines, and more often than not it tends to be right when I examine its suggestions closely.  For instance, I've previously examined the 13.Nxh7 sacrifice in Thiele-van Perlo, corr. 1987 in the Göring Gambit in the following position:

My previous examinations of the position suggested that 13.Nxh7 was dubious, and that 13.Ne6 was better, but a further examination with Stockfish suggests that 13.Ne6 is dubious because of 13...Bxe6 14.fxe6 and now the computer inconveniently points out 14...Ng8!, after which I can't see how White makes further progress.  Meanwhile, 13.Nxh7 appears to be sound, and may well be the best move in the position.  Thiele rather erred after 13...Kxh7 14.Bh5 g5 15.fxg6+, when after 15...Kg7 the g6-pawn blocks White's avenues of attack.  After instead 15.h4, it appears that White has at least enough for the piece in all lines.

I decided to feed Stockfish 8 a position that David Norwood used to show computers back in the 1990s, and which is sometimes thus known as the Norwood Position:

 Highlighting how far computers have advanced in the past 20 years, Stockfish 8 doesn't even look at the rook on a5, recommending that White shuffle the king, although it does erroneously assess the position at -17 pawns in Black's favour (the correct assessment is that it's a draw!).  If you enter 1.bxa5, it immediately gives mate for Black in circa 18 moves.

More challenging for the computer is if you replace the b-pawn with a bishop:

No, this wasn't originally my idea.  I can't recall where I first read it, but it is discussed in the Computer Chess News Sheet June-July 1994, so this might well be where the revised position originates from.  I recall feeding it to Fritz and Rybka some time ago and both computers insisted on grabbing the rook, but it might have changed with the latest commercial versions.

Stockfish 8 recommends 1.Bxa5 for a couple of minutes, assessing it as -5.2 pawns in Black's favour, and gives 1.Bb4 (the correct move) as -9.5 pawns in Black's favour, but then it picks up on 1.Bxa5 b4!, and within another couple of minutes it rejects 1.Bxa5 and gives 1.Bb4 followed by shuffling the king as best.  So even the revised version no longer stumps today's strongest computers.

There are of course still blockade positions that are even beyond Stockfish 8, but as computer AI continues to improve, they have to be more and more inventive.  I'm left wondering how AlphaZero, with its Monte Carlo method of calculation, would fare.  We might never know!

Wednesday, 3 January 2018

Kasparov plays the Mason Gambit

Happy New Year everyone!

Just stumbled upon a game from last August where Garry Kasparov, like Magnus Carlsen before him, wheeled out the Mason Gambit in blitz (1.e4 e5 2.f4 exf4 3.Nc3!?).

Unlike Carlsen's opponent, Karjakin did venture the critical response 3...Qh4+ but then after 4.Ke2 he went for the rather passive 4...Qd8.  As it was a blitz game he probably wanted to "play it safe" and the idea isn't completely without merit, for 4...d6 5.Nf3 Qd8 is one of Black's better responses, as discussed by John Emms in his 2000 book Play the Open Games as Black, giving a Fischer Defence where White has two extra tempi but one of them is the undesirable Ke1-e2.  As "brabo" discussed at the forum some time ago, the most critical response of all is probably 4...Ne7 covering d5.

However, after the immediate 4...Qd8, Kasparov's continuation 5.d4 Nf6 (5...g5? 6.h4 doesn't work for Black) 6.Bxf4 regained the sacrificed pawn and led to a rather interesting middlegame where White relied on a strong centre to compensate for the exposed position of the white king.

It would seem that Kasparov lost his way into the early middlegame and was lucky to get a draw, but fair play to him for continuing in the spirit of the opening and going all-out, which is usually the best way to swindle a win or draw in a blitz game. 

43...Qc6+ would have won for Black, with the idea 44.Kg1 hxg6.  Instead 43...Qd2+? was played (it was a blitz game after all!) and Kasparov managed to get a draw.

Earlier on, the computer offers 7.e5 as a reasonable alternative to the 7.Bg5 played in the game, and also suggests 7.Nd5, although I would find it difficult to psychologically justify allowing the opening of the e-file towards the white king with ...Nxd5, exd5.

Tuesday, 19 September 2017

Update on the Urusov

It's been a while, but I finally completed my update of the Urusov Gambit coverage at 
I've managed to get the ChessBase dynamic diagrams working, which allow viewers to move the pieces.  The new ChessBase game replayers is, I think, a significant improvement over the old one but I found that having multiple instances of the replayer on one web page caused glitches, so I have chosen to provide links to the annotated examples that are published using the One Click Publishing feature.

As for the assessment of the gambit, the accepted lines still seem to be holding up well, but of the declining lines, 4...Bb4+ does, as Michael Goeller suggested a while ago, appears to be the main problem at high levels, if Black aims for equality by striking out in the centre with a well-timed ...d5.  However, in the database, Black tends to follow up 4...Bb4+ poorly, and so the move is scoring only 41% for Black.  The highest-scoring reply for Black is the more well-known 4...Nc6 transposing to the Two Knights Defence (where Black is scoring 49%).  Black is scoring 44% after grabbing the bait with 4...Nxe4.

For White, if faced with a prepared opponent, there are some ideas for unbalancing the position after 4...Bb4+.  There is 5.c3 dxc3 6.0-0 0-0 (6...cxb2 7.Bxb2 and as in many such lines, it is unclear if White has two pawns' worth of compensation, but White's initiative is extremely dangerous) 7.a3!? (7.bxc3 d5), which gives some compensation, though I'm not sure if it is objectively enough.  More definitely sound but less in the gambit-style are 6.bxc3 d5 7.cxb4!?, and 6...Bc5 7.e5 d5 8.exf6 dxc4 9.Qxd8+.

I don't expect to be giving up the Urusov anytime soon, having had a lot of fun with it in practice, but in view of 4...Bb4+ as well as 4...Nc6, I don't expect it to catch on among grandmasters either.