Open Games (1.e4 e5)

This is a list of the lines that I intend to have covered by the end of 2020 (some already have coverage, but it is set to be updated).

Index of lines after 1.e4 e5, with an early d4

Göring Gambit - 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.c3 (or 2.d4 exd4 3.Nf3 Nc6 4.c3) The Göring Gambit with 4...dxc3 5.Nxc3 is quite dangerous and probably fully sound, while sacrificing a second pawn with 5.Bc4 is more dangerous, but of more marginal soundness. White typically aims to develop quickly and launch a quick attack against f7, Black's main weak point. Regardless of its objective soundness, White's practical chances and results in the accepted lines of the gambit have proved pretty good. Black can, however, equalise quite easily by declining it with 4...d5, often leading to "isolated queen's pawn" positions with White relying on piece activity to compensate for having an isolated pawn on d4. 4...Nf6, 4...Nge7 and 4...d3 are other decent ways of declining, but are less likely to give Black full equality.

Scotch Gambit - 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Bc4 (or 2.d4 exd4 3.Nf3 Nc6 4.Bc4)
Includes coverage of the Two Knights Defence with d4 (after 4...Nf6) and the Giuoco Piano with d4 (after 4...Bc5 5.c3 Nf6). After 4...Nf6 5.0-0 Bc5 6.e5 we have the Max Lange Attack, but Black can deviate with the fully adequate 5...Nxe4.
The Scotch Gambit is definitely sound, but does not promise a theoretical advantage. Play can transpose into Göring Gambit lines if White follows up with c2-c3 on the 5th or 6th move, and Black replies with ...d4xc3, but Black's most critical responses to the Göring can be side-stepped (e.g. 4...Bc5 5.c3 dxc3 can be met by 6.Bxf7+ intending 6...Kxf7 7.Qd5+ and Qxc5, and 4...Bb4+ 5.c3 dxc3 can be met by 6.0-0 or 6.bxc3). Black can equalise by transposing into the aforementioned Two Knights and Giuoco Piano lines.

Danish Gambit - 1.e4 e5 2.d4 exd4 3.c3
This can transpose into lines of the Göring Gambit after Nf3 and ...Nc6, but there are some independent lines.
In general I don't think the Danish move order is as strong as Göring's version with the knights out, as for example 3...Qe7 and 3...Ne7 are both much stronger than they are with Nf3 and ...Nc6 inserted. Also, if White tries the second pawn sacrifice with 3...dxc3 4.Bc4 cxb2 5.Bxb2, 5...d5 is fully playable, aiming to give back one or both of the sacrificed pawns, whereas with Nf3 and ...Nc6 inserted, playing ...d5 makes far less sense because e4xd5 hits Black's knight on c6. On the other hand, there are certain lines where White may benefit from having the option of playing Ng1-e2 rather than Ng1-f3.

Urusov Gambit - 1.e4 e5 2.Bc4 Nf6 3.d4 exd4 4.Nf3 (or 2.d4 exd4 3.Bc4 Nf6 4.Nf3, or 2.d4 exd4 3.Nf3 Nf6 4.Bc4).
The Urusov Gambit appears to be fully sound and quite dangerous. White's idea is that after 4...Nxe4 5.Qxd4, White can quickly develop and put pressure on the black kingside, and Black has to be wary of playing ...h7-h6 and castling kingside because of the strength of various Bxh6 sacrifices. After 5...Nf6, White should play 6.Nc3 followed by 7.Bg5, as 6.Bg5 is well met by 6...Nc6 intending 7.Qh4 d5. With good play Black can reach equality, whether accepting the pawn with 4...Nxe4 or transposing into "Two Knights Defence with d4" lines with 4...Nc6, which I cover under the Scotch Gambit.

Max Lange Gambit - 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.0-0 Nf6 5.d4. This gambit can transpose into the Max Lange Attack after 5...exd4 6.e5 (which I cover under the Scotch Gambit) while avoiding the anti-Lange lines with ...Nxe4. Black's main alternative is 5...Bxd4 (not 5...Nxd4?! 6.Nxe5!), but White gets long-term compensation following 6.Nxd4 Nxd4 7.f4 or 7.Bg5. It appears to be reasonably sound as well as quite dangerous, but Black can equalise with good play. With this move order White needs to have something ready against 4...d6, after which 5.d4 is less effective, and White may well be better off reverting to a more positional approach with d2-d3.

Italian Gambit - 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.d4. Advocated by Jude Acers and George Laven in their repertoire book The Italian System and a Guiding Repertoire for White. This move order avoids the possibility 4.0-0 d6, but it does give Black some additional options. 4...Nxd4 may be playable in view of 5.Nxe5 Qe7, taking advantage of White not having castled yet, while 4...exd4 transposes to the Scotch Gambit with 4...Bc5. 4...Bxd4 often transposes into Max Lange Gambit lines with 5.Nxd4 Nxd4 6.0-0 Nf6, but White has the interesting alternative 6.Be3, while after 6.0-0 Black has the deviation 6...d6.

Index of lines after 1.e4 e5 2.Nf3 Nc6 3.Bc4 (or 2.Bc4) without an early d4

The Two Knights Defence, Traxler Counterattack: 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Bc5. 4.Ng5, attacking f7, is a critical test of the Two Knights Defence, for although Black can take advantage of White's violation of traditional opening principles by moving a piece twice early in the opening, Black has to sacrifice at least a pawn in order to do so sucessfully. The Traxler aims to bring the white king out into the open after 5.Nxf7 Bxf2+. Instead after 5.Bxf7+ or 5.d4 Black aims for compensation for a pawn. The Traxler is dangerous (especially if White goes all-out with 5.Nxf7) but of marginal soundness.

The nameless Two Knights Defence line with 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5. This is generally used as a gambit in order to punish White for moving a piece twice in the opening, following 5.exd5 Na5 (which is good enough for dynamic equality) or 5...Nd4 or 5...b5 (both of which are dangerous but of more marginal soundness). If instead Black recaptures with 5...Nxd5, it is White who gets to unleash a very promising piece sacrifice, with the Fried Liver Attack, 6.Nxf7, bringing the black king out into the open. 6.d4 has often been cited as a stronger reply, but Black has been doing alright after 6...Be6.

Evans Gambit - 1.e4 e5 2.Nf3 Nc6 3.Bc4 Bc5 4.b4. This has periodically been tried in serious grandmaster games, notably by Garry Kasparov and Nigel Short. The main reason for this is that while it is probably equal with best play, it is one of the more dangerous "open gambits" and it is also harder for Black to find a way to return the pawn and reach a safe equality than with many of the other "open gambits". It can be declined with 4...Bb6, but it is not clear if this equalises for Black. After 4...Bxb4 5.c3, 5...Ba5 is the most critical test of the gambit, but 5...Bc5, 5...Be7 and even 5...Bd6 have been tried quite often as well.

Boden-Kieseritzky Gambit - 1.e4 e5 2.Bc4 Nf6 3.Nf3 Nxe4 4.Nc3 Nxc3 5.dxc3 (or, via the Two Knights Defence, 2.Nf3 Nc6 3.Bc4 Nf6 4.0-0 Nxe4 5.Nc3 Nxc3 6.dxc3). This gambit is quite dangerous, but unsound. Following ...f6 (defending the pawn on e5) and then a few more accurate moves, White gets hacking chances but not really enough for a pawn. Black also has ways to return the pawn and reach equality, so I do not recommend this line for White in serious games, but it may prove a lot of fun for some players in blitz and casual games.

Two Knights Defence with 4.d3. If you fancy playing the Two Knights Defence with Black, enticed by the various attacking possibilities for both sides following 4.Ng5 and 4.d4, you will probably often run into the more positional response 4.d3. In some lines, particularly those beginning 4...Be7, Black can aim for a Ruy Lopez Marshall Gambit-style pawn sacrifice of the e5-pawn starting with ...d5, although the immediate 4...d5 is probably premature. There are also lines in which Black delays or avoids kingside castling and pushes the g and h-pawns forward.

Blackburne-Shilling Gambit - 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nd4?!. At one point it was thought that 4.Nxe5 Qg5! was winning for Black, but in fact after 5.Bxf7+ Kd8 6.0-0 Qxe5, White has two pawns and a strong centre and a misplaced black king as compensation for the piece, rather like in the Cochrane Gambit against the Petroff. I also cannot recommend this line for Black in view of 4.Nxd4 exd4, whereupon after 5.0-0 and a subsequent c2-c3, White can get a promising Danish/Göring Gambit type of attacking position without having to sacrifice anything.

Index of other non-Ruy Lopez lines after 1.e4 e5 2.Nf3

Latvian Gambit - 1.e4 e5 2.Nf3 f5?! Some of the lines of this gambit lead to fascinating complications and good attacking chances for Black, such as the Svedenborg Variation (3.Bc4 fxe4 4.Nxe5 d5, envisaging the exchange sacrifice 5.Qh5+ g6 6.Nxg6 hxg6 7.Qxh8 Kf7), which attracts a number of players to this gambit. Black can also play a sort of reversed King's Gambit following 3.exf5 e4. However, White has recently been demonstrating a substantial advantage with 3.Nxe5, following 3...Qf6 4.Nc4, 3...Nf6 4.Bc4 and 3...Nc6 4.Qh5+.

Elephant Gambit - 1.e4 e5 2.Nf3 d5?! This is another of those trappy but unsound gambits, though probably a little sounder than the Latvian. 3.exd5 is the most critical test, whereupon Black's main attacking tries are 3...e4, most often met by 4.Qe2 Nf6 5.Nc3 Be7 6.Nxe4, and 3...Bd6, whereupon 4.d4 e4 5.Ne5 is critical. At lower levels Black's results with this have been reasonable, suggesting that in rapid and casual games Black can have a fair amount of fun with it, but objectively White gets a larger than normal advantage out of the opening. Another common line is 3.Nxe5, but following 3...Bd6 4.d4 White probably gets just a small advantage.

Other ...f5 gambits - Philidor Counter Gambit (1.e4 e5 2.Nf3 d6 3.d4 f5), Rousseau Gambit (1.e4 e5 2.Nf3 Nc6 3.Bc4 f5), Calabrese Counter-Gambit (1.e4 e5 2.Bc4 f5). These are some of the less common gambits involving an early ...f5. The Calabrese Counter-Gambit is probably the soundest of these gambits (indeed it is probably sounder also than the Latvian Gambit), although 3.d3 (initiating a sort of reversed King's Gambit Declined) and 3.d4, intending 3...exd4 4.Nh3!, are both critical. The other two appear to be somewhat unsound, although in blitz and casual games they may provide some players with a fair amount of fun.

Cochrane Gambit - 1.e4 e5 2.Nf3 Nf6 3.Nxe5 d6 4.Nxf7. This is a very radical way to meet the Petroff Defence. Unlike many other such piece sacrifice lines, White does not generally aim for an immediate attack on the black king, but rather aims for long-term positional compensation, with two pawns for the piece, a strong centre, and long-term attacking chances against the exposed black king. In some games White ends up steamrollering Black with the central pawns. The Cochrane is probably not fully sound, but Black will have to grovel for a while in order to make the extra piece count, and Black has no good way to decline the knight sacrifice, and no easy way to return the piece and reach equality.

Halloween Gambit - 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Nxe5?! Again, with this piece sacrifice White intends to steamroller Black by advancing the centre pawns. Black especially has to beware of letting White establish a pawn on d6, as there are various lines where this pawn is worth at least a piece on its own. However, with White having only one pawn for the piece, it is easier for Black to return the piece and reach equality (and maybe more). Also, in the line 4...Nxe5 5.d4 Ng6 6.d5 Nb8, stopping White from getting in e4-e5 and then d5-d6, with accurate play White struggles to get adequate attacking chances. Thus, I cannot recommend this for White in serious games, but in blitz and casual games it can be a lot of fun.

Ponziani gambits for Black - 1.e4 e5 2.Nf3 Nc6 3.c3 d5. This line with 3.c3 can lead to various transpositions into Göring Gambit Declined variations, but there are also independent possibilities, particularly in the sharp 3...d5 variation. Black is not obliged to play a gambit after 3...d5, as the critical 4.Qa4 can be well met by 4...f6 or 4...Qd6, both of which give equal chances. However, I find Caro's gambit line 4...Bd7 5.exd5 Nd4 6.Qd1 Nxf3+ 7.Qxf3 attractive, and 4...Nf6 (the Leonhardt Gambit) is also playable - both of these have scored well for Black. If 4.Bb5, complications erupt after 4...dxe4 5.Nxe5 Qd5. 4.exd5 Qxd5 5.d4 tends to lead to Göring Gambit Declined lines with 4...d5.

Rubinstein's line in the Four Knights: 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Bb5 Nd4. While this line has a reputation as an equaliser for Black, it is also a gambit idea. The immediate 5.Nxe5 is not too challenging because of 5...Qe7, but White often goes a pawn ahead after 5.Ba4, which Black most often meets with 5...Bc5 or 5...c6, both of which involve sacrificing the pawn on e5. Both theory and practice have suggested that Black's compensation is sufficient. Instead White can try to focus on development with 5.0-0, or head for simplification with 5.Nxd4, the latter in particular tending to put off many players because it often leads to early queen exchanges and sterility. However, there is a way for Black to avoid such early queen exchanges if desired.

Belgrade Gambit - 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4 exd4 5.Nd5. This is a pawn sacrifice idea for White in the Four Knights Game. White's compensation appears pretty good if Black accepts the sacrifice with 5...Nxe4. The main problem with this gambit is that Black can decline it, with the dull but safe 5...Be7 and the more enterprising 5...Nb4 both having given Black a slight plus score in practice, although objectively the resulting positions are about equal. The relatively unexplored 5...Bc5, favoured by some computers, is also worth looking at.

Index of lines after 1.e4 e5 2.f4 (King's Gambit)

Sometimes White plays for a delayed King's Gambit via the Vienna Game, 1.e4 e5 2.Nc3, intending 2...Nc6 3.f4, whereupon best play for both sides is 3...exf4 4.Nf3 g5. I cover these lines via the King's Gambit move order 1.e4 e5 2.f4 exf4 3.Nf3 (King's Knight Gambit, below) 3...g5 4.Nc3 Nc6.
I haven't covered the Vienna on this site chiefly because of the line 1.e4 e5 2.Nc3 Nf6 3.f4 d5, which leads to very different positions.

King's Knight Gambit - 1.e4 e5 2.f4 exf4 3.Nf3. The King's Gambit has the drawback of weakening the white kingside as well as sacrificing a pawn, but aims to compensate by securing a strong centre, as well as having two central pawns vs. Black's one, and to launch attacks down the f-file in many cases. After Black accepts the gambit, 3.Nf3 is the most popular move, preventing ...Qh4+. It is probably sound, but Black can equalise with good play. Unlike most other gambit lines, Black scores better in practice by playing to hold onto the extra pawn with 3...g5, than by giving the pawn back with the perfectly adequate 3...d5 (Modern Defence). The 3...g5 lines often lead to board-wide chaos, and even after 3...d5 the complications are often quite considerable. Black has other decent options including 3...Be7, 3...d6, 3...Nf6 and 3...Nc6.

King's Bishop Gambit - 1.e4 e5 2.f4 exf4 3.Bc4. This move invites 3...Qh4+, but the white king turns out to be relatively safe after 4.Kf1, after which Black probably has to give back the pawn with 4...d5 to keep the chances level. 3.Bc4 also makes it harder for Black to hold onto the extra pawn, for after 3...g5?! 4.h4, 4...g4 does not hit a knight on f3. Black's most popular response has tended to be 3...Nf6 4.Nc3 c6, intending ...d5, which leads to dynamically equal chances. However, as John Shaw pointed out in his book on the King's Gambit, 3...Nc6 is the most critical test of 3.Bc4, envisaging 4.Nf3 g5, transposing to 3.Nf3 g5 4.Bc4 Nc6. My conclusions aren't quite as strong as his, as I think White can equalise with best play after 4.d4, and maybe after 4.Nf3 as well, but after 3...Nc6 it does seem that White is the one fighting to keep the chances level.

Mason Gambit - 1.e4 e5 2.f4 exf4 3.Nc3. This is an extremely provocative move, encouraging 3...Qh4+ 4.Ke2. It is not fully sound, due to the uncomfortable position of the white king, but leads to fascinating complications. In the 20th century 4...d5 was the standard response, returning the pawn in order to get at the white king, but it seems that White can get at least an equal game against this starting with 5.Nxd5. The most critical responses are 4...Qe7, 4...Ne7 and 4...d6, all of which give Black good chances of an edge, albeit in a complicated position. Instead, 3...Nc6 transposes to the Vienna Gambit (1.e4 e5 2.Nc3 Nc6 3.f4 exf4) whereupon 4.d4!?, the Steinitz Gambit, is an independent alternative for White which is covered in this section also. Alternatively White can play 4.Nf3, transposing to 3.Nf3 lines and preventing ...Qh4+.

Falkbeer Counter Gambit - 1.e4 e5 2.f4 d5. This can be used as a more forcing way of getting into Modern Defence lines following 3.exd5 exf4 (here 4.Nf3 would transpose to 2...exf4 3.Nf3 d5 4.exd5). Falkbeer's original idea was to use it as a gambit, intending 3.exd5 e4, taking the f3-square away from the white king's knight. However, White has good chances of getting some advantage starting with 4.d3, immediately challenging Black's advanced e-pawn. Another way of gambiting a pawn is Nimzowitsch's 3...c6, although this probably doesn't fully equalise for Black either.

King's Gambit Declined - 1.e4 e5 2.f4 Bc5. Black has various ways to ignore the pawn sacrifice, but this is the most important and challenging way, covering the g1-square and thus making White's kingside castling difficult. 3.Nf3 d6 usually follows, and then White chooses between 4.Nc3, and 4.c3 aiming for d2-d4. With best play Black can probably reach equality, but in practice White is scoring around 55% against it. If Black wants to head for dynamic equality against the King's Gambit, the Modern Defence approach with an early ...d5 strikes me as rather more appealing.

Black gambits against the Ruy Lopez (1.e4 e5 2.Nf3 Nc6 3.Bb5)

Schliemann (or Jaenisch) gambit - 1.e4 e5 2.Nf3 Nc6 3.Bb5 f5. This is probably the most reliable of Black's gambit lines with an early ...f5, as in the Lopez White is not as well-placed to exploit the weakening of Black's kingside. It has also been played sporadically at grandmaster level. The main lines are 4.d3 fxe4 5.dxe4 Nf6, and 4.Nc3 fxe4 5.Nxe4, whereupon Black chooses between 5...Nf6 and 5...d5, where the latter leads to a brief flourish of complications. My feeling is that this gambit is just a little short of being fully sound, making it a reasonable weapon against the Ruy Lopez.

Deferred Steinitz - 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 d6.
White has various options here including 5.Bxc6+ and 5.Nc3, but the most critical answers are probably 5.c3, aiming for d2-d4, and 5.0-0. I will focus on the aggressive responses to these two lines, namely 5.c3 f5 (the Siesta Variation) and 5.0-0 Bg4 intending 6.h3 h5 (which Timothy Taylor has christened the Yandemirov Gambit, due to the late Valeri Yandemirov's frequent use of the line). The Siesta Variation often involves a pawn sacrifice, while in the line 5.0-0 Bg4 6.h3 h5 Black sometimes sacrifices the bishop on g4 in return for attacking chances down the h-file. The latter line in particular is of marginal soundness, but both lead to unusually wild play for the Ruy Lopez. In this section I also examine the closely related line of the Exchange Ruy Lopez, 4.Bxc6+ dxc6 5.0-0 Bg4, which is more definitely sound.

Finally, some may be disappointed that I am not planning to delve into the Marshall Attack (1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.0-0 Be7 6.Re1 b5 7.Bb3 0-0 8.c3 d5!?).

It's not because of the objective or practical merits of the line - I believe that it is the soundest pawn sacrifice that Black can try against the mainline Ruy Lopez, as well as one of the most dangerous, and the top grandmasters have been unable to find a clear route to an advantage for White against it. In addition Black has scored a very respectable 49% with it in the Chesslive.de database at the time of writing.

The main problem is that it is massively theoretical - to cover it would be a massive undertaking - and that below international master level Black's chances to play it will most likely be very few and far between, as White has all sorts of deviations such as 4.Bxc6+, 5.d3, 5.d4, 6.Qe2 and 8.a4.

However, I have covered some very similar ideas for Black in the Two Knights lines with 4.d3 Be7.