Thursday 27 February 2014

Critical lines of the Blackmar-Diemer Gambit Part 2: 5...e6, brief word on King's Gambit

The line with 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6 is generally known as the Euwe Defence.


Black blocks in the c8-bishop but increases the control over the d5-square and prepares to counterattack against d4 with ...c7-c5 or ...Nb8-c6.  White normally pins the f6-knight with 6.Bg5 and Black normally parries the pin with 6...Be7, for while the immediate 6...c5 is playable, it does not present White with any trouble getting enough compensation for the pawn.

Traditionally the most popular move is then 7.Bd3, aggressively eyeing the h7-pawn and thus making the immediate 7...0-0 inadvisable (while it doesn't lose by force, White gets an extremely dangerous attack with the standard moves 0-0, Qe1, Qh4 etc, and 8.Qd2 and 8.Qe2 intending 0-0-0 are also playable).  More challenging is 7...c5 but then after 8.dxc5 Qa5 (or 8...Nc6) White can consider 9.Qe2 and 9.Qd2, as well as the main line 9.0-0.

My problem with 7.Bd3 is that Black can take advantage of White neglecting the defence of the d4-pawn, and also threaten to chop off the bishop by playing ...Nb4, by playing 7...Nc6.





What does White do about the attack on the d4-pawn and the threat to take on b4?  Of course Black cannot take on d4 immediately because of Nxd4 and if ...Qxd4??, then Bb5+ picks up the queen, but the threat lingers over White.  Christoph Scheerer made a case for 8.a3, preventing ...Nb4,  but I think it may be too slow to give White full compensation for the pawn, and 8.Qd2 Nb4 allows the trade of the d3-bishop.  This leaves Lev Zilbermints's preference 8.0-0, sacrificing the pawn (since 8...Nxd4 9.Nxd4 Qxd4 is check) and intending 8...Nxd4 9.Kh1.  This line is likely to be effective at fast time limits but I think that objectively Black can get quite a large advantage after both 9...Nc6 (recommended by Craig Evans at the Chesspublishing.com forum) and 9...c5 (which I discussed at length with Mark Morss and a few others under the name "SWJediknight")- the discussion can be found at http://www.chesspub.com/cgi-bin/yabb2/YaBB.pl?num=1133589453/195

Therefore I recommend that White instead plays 7.Qd2 and I cannot find a way for Black to stop White from generating enough of an attack to compensate for the pawn.  If 7...h6 then 8.Bf4 works out quite well for White, and if 7...0-0 then White can probably get enough play with both 8.0-0-0 and 8.Bd3.  Castling queenside means that in many lines, ...c7-c5 and ...c5xd4 can be met by Rd1xd4.  My in-depth analysis of 5...e6 is featured in the third illustrative game at http://tws27.50webs.com/chess/blackmar_diemer_gambit/bdg4.htm

Therefore I don't regard 5...e6 as particularly worrying for BDG fans from a theoretical perspective.  The other three main lines, 5...Bf5, 5...g6 and 5...c6, however, may be a different matter. 


In the meantime I have ordered John Shaw's "telephone directory" of a book on the King's Gambit- it will be interesting to compare his conclusions on the opening with mine, especially as we appear to have common ground (his main recommendation against the early ...g5 approaches is the Quaade Gambit, which I currently consider to be the most promising option for White).  I hear that he regards 1.e4 e5 2.f4 exf4 3.Bc4 to be refuted by 3...Nc6, but as Stefan Bucker noted at Chesspublishing.com, this depends on whether or not Black can get an advantage in the Hanstein Gambit lines that follow 4.Nf3 g5, as well as the 4.d4 lines.  I'll reserve judgement on this until I get my copy of the book, but I was unable to find a route to advantage for Black in my online analysis of the Hanstein, and from a practical perspective, I can say that I've had several more online games as Black in the Hanstein recently and the resulting middlegames have usually been dynamically equal.

Wednesday 26 February 2014

The critical main lines of the Blackmar-Diemer Gambit Part 1 5...Bg4

I have updated my analysis of the main lines of the Blackmar-Diemer Gambit starting with 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3.
http://tws27.weebly.com/blackmar-diemer-gambit.html
http://tws27.50webs.com/chess/blackmar_diemer_gambit/bdg4.htm

I don't think that White has too much trouble generating enough compensation for the pawn against 5...Bg4 or 5...e6, but 5...Bf5, 5...g6 and 5...c6 all pose White some theoretical problems.  White always gets some attacking chances though.


After 5...Bg4 Black threatens to undermine White's d4-pawn and continue developing actively, so White typically forces the issue with 6.h3, whereupon Black can retreat the bishop with 6...Bh5 and 7.g4 Bg6 8.Ne5 follows.  The most critical continuation is then probably 8...e6 9.Bg2 c6, where Black sets up a solid formation similar to the Caro-Kann Defence.


Here Black's idea is to meet 10.h4 (threatening to trap the bishop on g6) with 10...Bb4, pinning the knight on c3 and preparing kingside castling.  After 11.0-0 Nbd7 I recommend that White respond to the challenge on the knight on e5 with 12.Nxg6 rather than 12.Qe2.  I also think 10.Rf1!? is a good option for White, bringing a rook to the f-file immediately and intending queenside castling, which will give White more scope to push the g and h-pawns without leaving the white king exposed.  Christoph Scheerer didn't treat this line well in his book, referring to a game where White played poorly and drifted into a losing position.

Traditionally, the main line sees Black chop off the f3-knight with 6...Bxf3 7.Qxf3 c6.






Here the traditional main line is 8.Be3, followed by a slow kingside build-up, but a few sources (notably "ArKheiN" at the Chesspublishing.com forum, and Christoph Scheerer in his book) have persuaded me that the more daring 8.g4!? is the way for White to go.  The idea is, instead of quietly completing development, to chase the f6-knight away with g4-g5 and blast through down the f-file, even at the cost of a second pawn.  White appears easily able to get enough compensation for the pawn if Black doesn't take on d4, so 8...Qxd4 is critical, but it appears that White can get two pawns' worth of compensation.  This line has proved a lot of fun at the local chess club.  8...Qxd4 9.Be3 Qe5 10.0-0-0 e6 11.g5 Nd5? 12.Nxd5 cxd5 13.Bf4 Qe4 14.Qxe4! dxe4 15.Bxb8 Rxb8? 16.Bb5+ is one trap that is easy for Black to fall into.  Black plays natural moves and swaps the queens off, but ends up falling for a mating attack.

Of course, this doesn't mean that the BDG is theoretically good for White, because Black has three options that are rather more critical than 5...Bg4, but in practice, 5...Bg4 is the most popular of Black's fifth-move options so if you play this opening frequently with White you will regularly face it.  I will shortly write brief articles on Black's other fifth-move options, but for now, those interested in seeing my in-depth coverage of the other lines can check out the links provided above.


Sunday 16 February 2014

A recent game in the French Defence

Been quite busy with other things recently but I know I should update this blog more often- something to correct over the coming months!

The next updates on my chess openings site will focus on the Two Knights Defence and Evans Gambit, and I also intend to update my coverage of the Blackmar-Diemer Gambit.

I recently won a nice "short and sweet" game in the French Defence, Rubinstein Variation, with 1.e4 e6 2.d4 d5 3.Nc3 dxe4.  Here I don't trust 4.f3 because of 4...Bb4- I suppose White could transpose to a Winkelmann-Reimer Gambit with 5.a3 Bxc3+ 6.bxc3, but I believe that Black can get the better game with either 6...c5 (I was involved in a discussion on this line at the Chesspublishing.com forum a while ago) or 6...e5 (recommended by John Watson in Play the French 4).  It is, to my mind, an inferior relative of the normal Blackmar-Diemer Gambit.  So I went for the normal line with 4.Nxe4.



Far more common at move 9, according to the Chesslive.de database, is 9.Bh4, which I am guessing is because Black can force the bishop to retreat (unless White is prepared to concede the bishop-pair) with ...Nf6-d5.  During the game I fancied keeping open the option of sacrificing on h6 following Qd2.  The sacrifice was probably sound already at move 11, but I decided to defer it for another couple of moves, noting that in the Urusov Gambit such sacrifices tend to be deadly if White's rooks are already on d1 and e1, while I think Black's queenside fianchetto plan was too slow and ...c7-c5 was called for much earlier.  According to the computer, Black's only way to avoid disaster after the sacrifice was to flick in 13...c4 14.Bxc4 gxh6, when White has excellent compensation for the piece but nothing decisive.  I had a forced mate with 16.Rh5 but the 16.Bxe4 played in the game was sufficient to win.