Friday 22 August 2014

John Shaw's Kings Gambit book plus a look at the Halloween Gambit

A brief look at the Halloween Gambit

The Halloween Gambit is an aggressive but dubious piece sacrifice in the Four Knights Game, 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Nxe5?!, which I have used about half a dozen times in casual games at the local chess club (though I would never use it in a serious tournament or match game).



White's idea is that after 4...Nxe5 White can strive to crush Black using the central pawns and force Black's knights to retreat to passive positions.  To my mind, the fact that White may objectively only be slightly worse after such a continuation reflects upon how rich in possibilities chess is.  If Black tries to hold onto the extra piece then White generally gets significant (though often not full) compensation for it.  One popular line runs 4...Nxe5 5.d4 Nc6 6.d5 Ne5 7.f4 Ng6 8.e5 Ng8 9.d6 cxd6 10.exd6, which gives White an imposing pawn on d6.


If Black plays ...Qb6 or ...Qf6 and then plays ...Kd8 to prevent the loss of the a8-rook to Nb5-c7+, then White generally gets good compensation for the sacrificed knight, although there is a flaw in this variation (with 10...Qf6 11.Nb5 Nxf4!, sacrificing the rook on a8, Black gets very good attacking chances).  

The other main accepted line of the gambit is 4...Nxe5 5.d4 Ng6 6.e5 Ng8 7.Bc4.  Here the most critical response is probably Max Euwe's 7...d5 8.Bxd5 c6 (8...N8e7 is also good), where White maintains compensation for the piece but with best play Black should be slightly better.

Thus the Halloween Gambit can be successful in rapid games and is the sort of line that can provide fans of unorthodox openings with a lot of fun.  However, I don't recommend it for use in serious games because Black has various ways to return the piece and reach at least an equal game, the biggest problem being Jan Pinski's suggestion 5...Nc6 6.d5 Bb4, which generally results in Black getting the majority of the attacking chances.  Indeed, even 5...Bd6 6.dxe5 Bxe5 looks at least equal for Black.  I have seen people compare the Halloween Gambit to the Cochrane Gambit, but this issue represents the most important difference between the two- in the Cochrane Black has no way to return the piece early in the game and come close to reaching equality, let alone a better position, and so must hold onto the piece and withstand White's attempts to squeeze Black using the central pawns.

The King's Gambit and John Shaw's book

After this bit of light entertainment, some "heavier" stuff is in order.  I intend to return to the Evans Gambit soon with a look at the declined variations, but for now, I feel it is time to update my coverage of the King's Gambit, especially in view of the large book that came out on the opening by John Shaw, and to expand upon it, as I don't think I got around to covering the declined variations (notably the Falkbeer and 2...Bc5- I have faced 2...Bc5 a few times from the white side recently as well).

My general opinion of the book is favourable- it is an impressively thorough coverage, and Shaw has come up with a number of suggestions for both sides that I hadn't considered, so there is plenty to examine.  He also agrees with me that the Quaade Gambit approach vs. the ...g5 lines (with an early Nf3 followed by Nc3) is probably White's best way to generate unbalanced, open-ended and equal play.  However, on the downside, I think he is too dismissive of some sidelines that fall outside of his main repertoire, most notably the King's Bishop Gambit (I have used 3...Nc6 as my main antidote to 1.e4 e5 2.f4 exf4 3.Bc4 for about six years, but I feel that calling it a refutation is too strong- I think White should be able to reach equality in the 4.d4 lines and maybe 4.Nf3 also) and the piece sacrifice lines of the Rosentreter for instance.  

Another important source that I expect to be using is the Chess-Brabo blog, which contains an interesting discussion on the Fischer Defence vs. the Quaade Gambit.  I definitely need to revisit those lines, especially as I sometimes get them from both sides of the board (mainly White, but I've had a couple of games as Black which reached these lines via transposition also).

Thursday 21 August 2014

The Cochrane Gambit vs the Petroff

Many 1.e4 players are frustrated by the Petroff Defence, 1.e4 e5 2.Nf3 Nf6, whereupon if White grabs the pawn on e5, 3.Nxe5, then 3...d6 follows, encouraging 4.Nf3 Nxe4.  However, in the Cochrane Gambit, White instead speculatively sacrifices a knight on f7:  4.Nxf7.


http://tws27.weebly.com/cochrane-gambit.html

I was inspired to take a look at this line after examining David Bronstein's dubious piece sacrifice in the Two Knights Defence (1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5 6.d3 h6 7.Nf3 e4 8.dxe4 Nxc4).  The Cochrane Gambit, despite looking crazy at first glance, is rather sounder because White gets a similarly strong centre, and also leaves the black king misplaced.  Black often spends time getting the king into a relatively safe position which allows White to build up a space advantage.  Rather than aim for a quick attack against the black king, White generally seeks a slower build-up, aiming to crush Black by pushing the central pawns forward, although many lines also give White long-term attacking prospects against the black king.

After 4...Kxf7 White generally continues with 5.d4, since 5.Bc4+ is met by 5...d5.  If Black plays 5...Nxe4?! then White wins the knight on e4 with 6.Qh5+ g6 7.Qd5+, or 6...Ke7 7.Qe2.  My examinations of the line have suggested that the line 5.d4 g6 6.Nc3 (if 6.Bc4+ Kg7 7.Nc3 Be7) 6...c5 may be the hardest line to crack, where Black aims to put the king on g7 and play to undermine White's d4-pawn, encouraging a pawn swap on c5 and a queen swap on the d-file.

In most of the other lines White appears to be able to get sufficient compensation for the sacrificed knight without much difficulty.  For example, 5...d5 6.e5 Ne4 7.Bd3 leaves Black's knight unstable, 5...Be7 6.Nc3 c6 7.Bd3 Re8 8.0-0 is promising for White, and 5...Qe8 6.Nc3 c5 (suggested by John Watson) is fine for White after 7.Be3!? (a Rybka suggestion) and 7.Bc4+ Be6 8.d5.

5...c5 is tricky, since 6.Bc4+ is met by 6...d5 7.exd5 b5, and 6.Nc3 g6 transposes to 5.d4 g6 6.Nc3 c5, so White's best is probably 6.dxc5 Nc6 7.Bc4+ Be6 8.Bxe6+ Kxe6 (Short-Shirov, Dubai rapid 2002).  I am not sure if White's compensation is objectively 100% sufficient in that line, but with the black king considerably misplaced there will always be significant practical chances.  However, "Vass" at the Chesspublishing.com forum suggested 6...d5!?, which appears good for Black.

A deviation is 5.Nc3 (Topalov-Kramnik, Linares 1999) which is probably no better or worse than 5.d4 theoretically, as I haven't been able to find a way for White to avoid the transpositions to the critical line with ...g6 and ...c5, while Black's other responses tend to give White enough compensation.  The Topalov and Short games are both analysed in my site's games and analysis section.

I think that the Cochrane Gambit isn't 100% sound with best play, but it is close enough to giving White full compensation to be fully viable at club level and maybe a fair way beyond that.   Those who consider the knight sacrifice to be too risky could consider the line 4.Nf3 Nxe4 5.Nc3 Nxc3 6.dxc3 instead, while Michael Goeller wrote an extensive article on some approaches following 3.d4.

Another source on the Cochrane is Goeller's bibliography on the line.

Sunday 17 August 2014

The Evans Gambit Part 3- 5...Ba5, 7.0-0 Nge7, 7.Qb3

My investigations into the Evans Gambit Accepted are concluded with a look at the most critical lines following 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4 Bxb4 5.c3 Ba5 6.d4 exd4.  The illustrative examples are now complete as well.
http://tws27.weebly.com/evans-gambit-accepted.html

After this I envisage taking a little break from the Evans and looking at the Cochrane Gambit and maybe one or two other "lighter" lines before returning to the Evans and covering the declined variations, as 4...Bb6 in particular will quite often be encountered.  I also think it will be well worth revisiting my coverage of the King's Gambit, having read most of John Shaw's book and seen some discussion of the relevant lines at Chesspublishing.com.

The main problem with 7.0-0 has always been 7...Nge7 preparing to strike out in the centre with ...d7-d5.  In these lines White can generally regain the gambit pawn but Black has little trouble equalising.


For instance 8.cxd4 d5 leaves White with nothing better than 9.exd5 Nxd5, and White can typically regain the pawn by playing Qb3 and Qxb7 but Black ends up quite comfortable.
More aggressive is 8.Ng5 intending 8...d5 9.exd5 Ne5 (not 9...Nxd5? 10.Nxf7) and then White should play 10.Qxd4 rather than the retreat 10.Bb3.  Play can get quite complicated, but the complications quite often burn out to a draw or an equal endgame.

Thus Nigel Short has preferred 7.Qb3, attacking f7 and preventing Black from carrying out the ...Nge7 and ...d5 plan immediately.  Play then typically continues 7...Qf6 8.d4 Bb6 9.e5 Qg6 10.cxd4.



This offers the sacrifice of a second pawn on d4, which gives White dangerous compensation if accepted, so Black generally acquires the bishop-pair with 10...Na5, but 11.Qa4 Nxc4 12.Qxc4 still gives White reasonable compensation for the pawn due to the strong centre and open lines for the pieces.  Mihail Marin recommended 8...Nge7 but I am not sure that Black's life is so easy after 9.cxd4 Bb6 10.e5 Qf5 11.Ba3.  Black can try to return the pawn with ...d7-d6, but it is not a definite equaliser.

I think 7...Qe7 is also similarly playable, leading to dynamically equal play, but it is perhaps harder for Black to handle the resulting positions over the board.  8.d4 Bb6 (8...d6 and 8...Nf6 currently look likely to concede some advantage to White, in spite of the pawn minus) 9.cxd4 Nxd4 10.Nxd4 Bxd4 11.Nc3 is the usual continuation which gives White dangerous compensation for two pawns.

In conclusion, Black appears able to keep the chances level after 4...Bxb4 5.c3 Be7, 5...Bc5 and 5...Ba5 but in each case White appears able to ensure that it is a dynamic rather than sterile type of equality, so the accepted lines of the Evans are looking in reasonable shape from White's point of view as well.  I would say that 7.Qb3 is looking more promising after 5...Ba5 6.d4 exd4 because although the resulting positions are only equal, it is much harder for Black to return the pawn and reach easy equality.  I think that 5...Bd6 is interesting, but with best play White should be able to get some advantage against it.

Thursday 14 August 2014

The Evans Gambit Part 2- The Normal Position, 4...Bxb4 5.c3 Ba5 6.d4 d6 and the Compromised Defence

I've been busy during the last fortnight but have come out with the latest update on the Evans Gambit.
http://tws27.weebly.com/evans-gambit-accepted.html


Firstly, a recap on 4...Bxb4 5.c3 Be7.  In Nigel Short's preferred line, 6.d4 Na5 7.Bd3 d6, if White continues with 8.dxe5 then Black has the independent option 8...Bg4, as pointed out to me by Mark Nieuweboer, so White should in my opinion consider the move-order trick 8.0-0, intending 9.dxe5, and in that case 8...Bg4 is met by 9.Nbd2 reinforcing the knight on f3.

Instead, after 5...Bc5 6.d4 exd4 7.0-0 Bb6 8.cxd4 d6 (or 7.cxd4 Bb6 8.0-0 d6) we reach the so-called Normal Position.


Tim Harding wrote extensively about this in his two-part series about Chigorin and the Evans Gambit.  I don't really trust 9.d5 Na5 10.Bd3, but 10.h3, preventing 10...Bg4, might be good enough.  Instead 9.Nc3, the preference of Morphy and Chigorin, looks good enough to provide enough compensation for the pawn following 9...Na5 10.Bd3 Ne7 11.Nd5 (or 11.h3) and 10...Bg4 11.Nd5 (sacrificing a second pawn, also good is 11.Be3).  Black generally retains the extra pawn, so the "Normal Position" offers both sides good scope to play for a win.

Instead critical is 5...Ba5, whereupon after 6.d4 (I don't trust 6.Qb3 Qe7, followed by 7...Nf6, or 6.0-0 Nf6, both of which give Black chances to safely castle kingside) Black can play 6...d6 whereupon 7.0-0 Bb6 leads into Lasker's Defence.


Traditionally this has led to a double-edged game after a long and fairly forcing line: 8.dxe5 dxe5 9.Qb3 (9.Qxd8+ Nxd8 10.Nxe5 Nf6 is equal) 9...Qf6 10.Bg5 Qg6 11.Bd5 Nge7 12.Bxe7 Kxe7 13.Nxc6 Qxc6 14.Nxe5 Qe6 15.Nc4 Rd8.  However, Mihail Marin pointed out the deviation 11...f6 in Beating the Open Games, which appears to be better for Black, and was successful in Kogan-Anand, Venaco 2005.  Thus White should avoid this line.

Thus White tends to continue 7.Qb3 Qd7 and grandmasters have largely abandoned the old main line 8.dxe5, striving to open the d-file.  I am guessing that this is because of Black's method of returning the gambit pawn with 8...Bb6, rather than the attempt to hold it with 8...dxe5.  White typically gets better piece play, but an inferior pawn structure, e.g. 9.Nbd2 Na5 10.Qc2 Nxc4 11.Nxc4 d5 12.exd5 Qxd5 13.Ne3 Bxe3 14.Bxe3 Ne7 (Li-Ni, Manila 2007).

Nigel Short has tried out 8.Nbd2 Bb6 9.a4 which worked well for him in Short-Sargissian, Wijk aan Zee 2008, but 9...Nf6 may be a more critical test than the 9...Nh6 played in the game.

Finally we come to the Compromised Defence with 6...exd4 7.0-0 dxc3, which is reminiscent of some lines of the Danish and Goring Gambits, but with improved chances for White.  The most critical line runs 8.Qb3 Qf6 (8...Qe7 9.Nxc3 sets up the dangerous threat of Nc3-d5, and if 9...Bxc3 10.Qxc3 and if 10...f6 11.e5) 9.e5 Qg6 10.Nxc3.



Most reliable is 10...Nge7 11.Ba3 0-0, getting the king to comparative safety on the kingside, but White can generate very strong kingside threats, particularly with the black queen exposed on the kingside.  Computers tend to assess these positions as equal but in practice Black's defence is very difficult.

An interesting sideline after 7.0-0 is 7...Nf6!?, also examined by Tim Harding at one of his later articles (http://www.chesscafe.com/text/kibitz119.pdf).  I think White's best bet is probably 8.e5 rather than the old book recommendation 8.Ba3 and the resulting positions are somewhat messy, but Black has to exercise considerable care to navigate through the complications without trouble.

Of course my coverage of the Evans isn't finished- there is still 7.0-0 Nge7 and the 7.Qb3 lines to examine, which are probably the three most important lines for the theoretical assessment of the Evans.

Friday 1 August 2014

The Evans Gambit Part 1- 4...Bxb4 5.c3 Bd6, Be7

The Evans Gambit begins 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4.  Unlike most of the other "Open Gambits" that I have looked at so far, where White (or less commonly Black) sacrifices the d or e-pawn, in the Evans White sacrifices a wing pawn in order to gain time building up a strong centre with c2-c3 and d2-d4.  The coverage is expanding here: http://tws27.weebly.com/evans-gambit-accepted.html


The Evans Gambit is a complex line with numerous options along the way for both sides, so it will probably take quite a while to complete the coverage.  However, I feel that a site devoted primarily to romantic-style gambits would be incomplete without covering the Evans Gambit, which was especially popular at high levels of play during the late 19th century and is still played occasionally by grandmasters today, such as Nigel Short and Alexander Morozevich.  I also had a lot of success on the white side of the Evans during my junior chess playing days.  In some variations White can take advantage of the missing b-pawn by playing Bc1-a3 and catching the black king in the centre.

Black most often accepts the gambit with 4...Bxb4 (although the declined variation with 4...Bb6 is also important), whereupon White usually continues with the immediate 5.c3, attacking the black bishop.  Instead 5.0-0 is less convincing because Black can play 5...Nf6 and strive for rapid castling, something that Black often doesn't get time for in the lines following 5.c3 without making concessions.

5...Bd6


5...Bd6 is an unusual but fairly respectable move, reinforcing the pawn on e5.  The main problem with it is that Black blocks in the c8-bishop by blocking the movement of the pawn on d7, and this often leads to Black getting into a tangle in the early middlegame.  The usual continuation is 6.d4 Nf6 7.0-0 0-0 8.Re1, and then Black can try 8...h6 (preventing the plan of Nf3-g5 followed by f2-f4) 9.Nbd2 Re8,


whereupon White is doing quite well after both 10.Qb3 (attacking f7) and 10.Bd3 (getting the bishop out of the way of any ...Nc6-a5 tricks).  Note that after 10.Bd3, Tim Harding's recommendation 10...Bf8 11.Nxe5 Nxe5 12.dxe5 Rxe5 13.f4 is flawed because of 13...Bc5+ followed by 14...Rh5, so White should prefer 13.Nf3.

The 8...Qe7 used in the main illustrative game Berelowitsch-Andersen, Bundesliga 2014 is less convincing because White plays 9.Nbd2 and if 9...Re8 10.Nf1 (preparing Ng5 followed by f4) and Black has serious problems maintaining the strong-point on e5.

5...Be7

This is a more important response which is often used by grandmasters, as it offers Black good scope to return the gambit pawn and reach equality (or at least get very close to equality), whereas the more critical 5...Ba5 makes it easier for White to insist on playing for compensation for a pawn.

An old favourite of Tim Harding's is 6.Qb3!? which attacks the f7-pawn immediately.  Although Black can get in the ...Na5 fork (of the queen on b3 and bishop on c4) White can force concessions in the black kingside by playing 6...Nh6 7.d4 Na5 8.Qb5 Nxc4 9.Bxh6.


This line offers good practical chances, but be warned: objectively, I think it is flawed, because Black can play 9...gxh6 here and then follow up with ...Rg8, taking charge of the half-open g-file.  For example, 10.Qxc4 exd4 11.cxd4 Rg8 12.0-0 d5! 13.exd5 Bh3, as played in Asker-Tosti, Brazil 1998.  My main illustrative example is Morozevich-Bacrot, Sarajevo 2000, in which Black instead played 9...Nd6 and got equality.

More reliable is thus the main line with 6.d4 Na5 and then the traditional main line runs 7.Nxe5 Nxc4 8.Nxc4 d5 9.exd5 Qxd5 10.Ne3, where White has the better central control but Black has the bishop-pair.  Since this line is probably no better than equal for White, most grandmasters have experimented with alternatives in the last two decades.  Garry Kasparov tried 7.Be2 instead in the 1990s, whereupon Black should probably defend e5 with 7...d6 rather than allowing 7...exd4 8.Qxd4. 
Nowadays most grandmasters, including Nigel Short, prefer 7.Bd3, which leads to roughly equal play after 7...d6 8.dxe5 dxe5 9.Nxe5.  The game Short-Bruzon Batista, Poikovsky Karpov 2012, then continued 9...Nf6 10.0-0 0-0 11.Qc2 c5.


Short now played 12.f4, which allowed Black to generate counterplay on the queenside with 12...c4 and Black soon got the upper hand.  I think that 12.Nd2 is probably best, covering the c4-square, and only then 13.f4, after which I slightly prefer White's position.

Repertoire/move-order issues

Another enhancement to my chess site is the addition of a brief section detailing some repertoire/move-order issues that players of these lines might come across (these will gradually be established across the site as I add new articles and update old ones).  This was inspired partly by reading through some debates on the Evans Gambit at the Chesspublishing.com forum, where some members pointed out that a significant issue with the Evans Gambit is that White has to be prepared to face the Two Knights Defence (3...Nf6), which is also the main reason why I rarely face the Evans Gambit from the black side.

From White's point of view I would recommend either 4.Ng5 or 4.d4, depending on taste (the line 4.d4 exd4 is covered on my site via the Scotch Gambit), since 4.d3 tends to lead to relatively closed, slow games (especially if Black goes for solid defence rather than the more aggressive set-ups based on ...d7-d5 and/or ...f7-f5) and the Boden-Kieseritzky Gambit is currently looking somewhat dubious.