Chess Opening Theory/1. e4/1...e5/2. Bc4/2...Nf6

Berlin defence C24 Bishop's opening 2...Nf6 · Berlin defence Black develops the king's knight and threatens the e4-pawn. This move also pre-empts "scholar's mate" by controlling the h5 square so preventing 3. Qh5. Defend the pawn White's e4-pawn is under attack. Exactly how they choose to defend it presents different options for transpositions (Italian game positions or Vienna game positions). 3. d3 is the main line. This is the most straight forward way to defend the pawn and puts paid to the idea of ...Nxe4. It also opens a line for the queen's bishop to develop. Most commonly, Black may invite White to transpose into an giuoco pianissimo via a couple of move orders (3...Nc6 4. Nf3 Bc5 is one). However, Black's most testing idea is to capitalise on the fact that they have not needed to play ...Nc6 yet by playing 3...c6, avoiding transposing and preparing to play ...d5. 3. Nc3 is a transposition into the Stanley variation of the Vienna game. This appears to add a defender to e4, but the defence, for the moment, is illusory. If 3...Nxe4, 4. Nxe4? is a mistake on account of a common tactic called the centre fork trick. (4...d5! 5. Bd3 dxe4 6. Bxe4 f5 7. Bf3 --). It's not cut and dry, however, because White can regain the material another way, 4. Qh5 (threatening Qxf7#) Nd6 (best) 5. Qxe5+ . Usually Black wishes to avoid this, and first defends e5, 3...Nc6, and if White wishes to avoid the centre fork trick, they are compelled to play 4. d3 to defend the pawn after all. This is a fine move, but it does allow Black to seize the bishop pair with 4...Na5. 3. f3? to defend the pawn should not be played: it is unnecessarily weakening to White's king's side, and takes away the most active developing square for the king's knight. Gambit a pawn White may rather give up a pawn for activity and attacking chances. After 3. d4!?, the Ponziani or Urusov gambit, White offers either pawn for Black to take. After 3...exd4, White allows Black the option of keeping the material: 4. Nf3 Nxe4 5. Qxd4 Nf6 . 4...Nc6 instead and the game reaches a tabiya more commonly seen in the 4...Nf6 line of the Scotch gambit (also arising from 4. d4 in the Italian game two knights defence). Either way White has active play and compensation for the pawn. 3...Nxe4? however is wrong: 4. dxe5 and White is looking for sacrifices or attacks on f7, e.g. 4...Nc6 5. Bxf7+ Kxf7 6. Qd5+ Ke8 7. Qxe4 ++. 3. Nf3 allows Black to take on e4, 3...Nxe4. Though 4. Nxe5 may be played, (Black is doing well after 4...d5), the usual idea is to sacrifice the pawn with 4. Nc3!?, the explosive Boden-Kieseritzky gambit. 4...Nxc3 5. dxc3 and White has a lot of activity. Many amateurs have fallen afoul of 4...d6?? 6. Ng5! Be6 7. Bxe6 fxe6 8. Qf3!only +++. However, Black can avoid all the complications with 3...Nc6, and instead transpose into two knights defence to the Italian game. 3. f4 is a gambit explored by Gioachino Greco. Accepting the pawn, 3...exf4?!, would transpose into a less common line in the king's gambit accepted, but better refutations are to be had with 3...Nxe4 or 3...d5. History The earliest games in this line were recorded by seventeenth century chess author Gioachino Greco (1600―1634), including the line with 3. f4, known as the Greco gambit.NN v Greco, 1620. Chessgames.comGreco v NN, 1620. Chessgames.com Domenico Ponziani (1719―1796) published analysis of the defence, though focused more on the line with 2...Bc5.The incomparable game of chess "dal Rio" "Ercole" 1820 228-232 English https://babel.hathitrust.org/cgi/pt?id=hvd.hn4zcu Bingham J. S. 1769 London J. J. Stockdale (N.B. as a historical curiousity, the translator incorrectly attributed this to Del Rio rather than Ponziani) Before Jaenisch, 2...Nf6 was considered inferior to 2...Bc5. Jaenisch praised 2...Nf6 as the strongest, counterattacking reply, writing in 1842 that it "proves... the relative weakness of [2. Bc4, and] It is difficult for us to conceive how all preceding authors have, without exception, dismissed [2...Nf6] as inferior to [2...Bc5], which latter move so decidedly yields a vast field of attack for the first player."Jaenisch's chess preceptor: a new analysis of the openings of games de Jaenisch C. F. Longman & co. 1847 London https://archive.org/details/jaenischs-chess-preceptor Walker George 64-71 (translation of Analyse nouvelle des ouvertures du jeu des échecs de Jaenisch C. F. Gartner 1842) It was given the name Berlin defence (in German, Berliner partie) by von der Lasa in Handbuch des Schachspiels (first published 1843), who attributed it to Berliner Ludwig Bledow (1795―1846).Handbuch des Schachspiels von Biluger P. R. Verlag Von Veit & Comp. 1891 7th Leipzig https://archive.org/details/handbuchdesscha00schagoog 363-374 Theory table 1. e4 e5 2. Bc4 Nf6 3 4 Modern Bishop's Opening d3Nc6 Nf3Be7equal Ponziani/Urusov Gambit d4!? = Vienna Gameby transposition Nc3equal Petrov's Defenceby transposition Nf3-1 References See also Bishop's Opening fi:Shakki/rnbqkb1r;pppp1ppp;5n2;4p3;2B1P3;8;PPPP1PPP;RNBQK1NR w KQkq