The Evans Gambit is a chess opening characterised by the moves: The Evans Gambit is an aggressive line of the Giuoco Piano. White offers a pawn to divert the black bishop on c5. If Black accepts, White can follow up with c3 and d4, ripping open the, while also opening diagonals to play Ba3 or Qb3 at some point, preventing Black from castling and threatening the f7-pawn respectively. If Black declines, the b4-pawn stakes out on the queenside, and White can follow up with a4 later in the game, potentially gaining a tempo by threatening to trap Black's. According to Reuben Fine, the Evans Gambit poses a challenge for Black since the usual defences are more difficult to pull off than with other gambits. The Encyclopaedia of Chess Openings has two codes for the Evans Gambit, C51 and C52.
The gambit is named after the Welsh sea Captain William Davies Evans, the first player known to have employed it. The first game with the opening is considered to be Evans–McDonnell, London 1827, although in that game a slightly different move order was tried. In 1832, the first analysis of the gambit was published in the Second Series of Progressive Lessons by William Lewis. The gambit became very popular shortly after that, being employed a number of times in the series of games between McDonnell and Louis de la Bourdonnais in 1834. Players such as Adolf Anderssen, Paul Morphy and Mikhail Chigorin subsequently took it up. The Evergreen game won by Adolf Anderssen against Jean Dufresne opened with the Evans Gambit. Eventually however, the second World Chess ChampionEmanuel Lasker dealt a heavy blow to the opening with a modern defensive idea: returning the pawn under favourable circumstances. The opening was out of favour for much of the 20th century, although John Nunn and Jan Timman played some games with it in the late 1970s and early 1980s, and in the 1990sGarry Kasparov used it in a few of his games, which prompted a brief revival of interest in it.
General remarks
Accepting the gambit
The most obvious and most usual way for Black to meet the gambit is to accept it with 4...Bxb4, after which White plays 5.c3 and Black usually follows up with 5...Ba5. White usually follows up with 6.d4. Emanuel Lasker's line is 4...Bxb4 5.c3 Ba5 6.d4 d6 7.0-0 Bb6 8.dxe5 dxe5 9.Qxd8+ Nxd8 10.Nxe5 Be6. This variation takes the sting out of White's attack by returning the gambit pawn and exchanging queens, and according to Fine, the resulting simplified position "is psychologically depressing for the gambit player" whose intent is usually an aggressive attack. Chigorin did a lot of analysis on the alternative 9.Qb3 Qf6 10.Bg5 Qg6 11.Bd5 Nge7 12.Bxe7 Kxe7 13.Bxc6 Qxc6 14.Nxe5 Qe6, which avoids the exchange of queens, but reached no clear verdict. Instead White often avoids this line with 7.Qb3 Qd7 8.dxe5, when Black can return the pawn with 8...Bb6 or hold onto it with 8...dxe5, though White obtains sufficient compensation in this line. Alternatively Black can meet 6.d4 with 6...exd4, when White can try 7.Qb3, a move often favoured by Nigel Short. 7.0-0 is traditionally met by 7...Nge7 intending to meet 8.Ng5 or 8.cxd4 with 8...d5, returning the pawn in many lines, rather than the materialistic 7...dxc3 which is well met by 8.Qb3 with a very dangerous initiative for the sacrificed pawns. Alternatively 7...d6 8.cxd4 Bb6 is known as the Normal Position, in which Black is content to settle for a one-pawn advantage and White seeks compensation in the form of open lines and a strong centre.
Declining the gambit
Alternatively, the gambit can be declined with 4...Bb6, when 5.a4 a6 is the normal continuation. But due to the loss of tempo involved, most commentators consider declining the Evans Gambit to be weaker than accepting it, then giving up the pawn at a later stage. Also, Black can play the rare Countergambit Variation, but this is thought to be rather dubious. In the book My System, however, Aron Nimzowitsch states that by declining the gambit Black has not lost a tempo, since the move b4 was, in the sense of development, unproductive,
as is every pawn move, if it does not bear a logical connection with the centre. For suppose after 4...Bb6 5.b5, 5...Nd4 and now if 6.Nxe5, then 6...Qg5 with a strong attack.
Bishop retreats after accepting the gambit
After 4.b4 Bxb4 5.c3, the bishop must move or be captured. The common retreats are listed here, with the good and bad sides of each:
5...Ba5
According to Chessgames.com, this is Black's most popular retreat. It gets out of the way of White's centre pawns, and pins the c3-pawn if White plays 6.d4, but it has the disadvantage of removing the a5-square for the black queen's knight. Black usually subsequently retreats the bishop to b6 to facilitate...Na5, which is particularly strong when White opts for the Bc4, Qb3 approach.
5...Bc5
According to Chessgames.com, this is the second most popular retreat, with White scoring better than after 5...Ba5. This is often played by people unfamiliar with the Evans Gambit, and is arguably inferior to 5...Ba5, because 6.d4 attacks the bishop and narrows down Black's options as compared with 5...Ba5 6.d4.
5...Be7
Lasker's Defence has often been considered one of the "safer" retreats, and has been played by Viswanathan Anand. After 6.d4 Na5, White can attempt to maintain an initiative with 7.Be2 as played by Kasparov, or immediately recapture the pawn with 7.Nxe5.
The Evans Gambit was referenced in The West Wing episode "Hartsfield's Landing", when President Josiah Bartlet mentions it while playing with Toby Ziegler.
