A solid opening for amateurs is the Scotch Four Knights (C47), which generally arises via the Scotch move order 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 5.Nc3 but can also come out of a Four Knights (1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.d4) or Vienna move order (1.e4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.d4). I personally use the Vienna move order to avoid the annoying Petroff Defense and to meet a Philidor set-up with an f4 advance, though you need to be aware that after 1.e4 e5 2.Nc3 Nf6 3.Nf3 Nc6 4.d4 Black has the interesting gambit 4...Bb4!? (originated in Paulsen - Morphy, New York 1857) which is not available in the Scotch move order.
The long main line of the Scotch Four Knights goes 1.e4 e5 2.Nf3 Nc6 3.d4 exd4 4.Nxd4 Nf6 (in this move order, White has to know various anti-Scotch ideas, including Steinitz's 4...Qh4!?) 5.Nc3 (5.Nxc6 bxc6 6.e5 is the more popular Mieses Variation) 5...Bb4 (5...Bc5!? is also playable) 6.Nxc6 (White also has the strange 6.Bb5!?) 6...bxc6 7.Bd3 (7.Qd4!? Qe7 8.f3 can be complicated but seems playable and was a favorite of Paulsen) 7...d5 (Black can also delay this advance and play 7...O-O 8.O-O with perhaps ...Re8 or ...d6) 8.exd5 cxd5 9.O-O O-O 10.Bg5 c6 reaching the standard tabiya, when White can consider 11.Qf3, 11.Na4, or 11.Ne2, all of which are considered roughly equal.
Though considered equal by theory, the Scotch Four Knights is quite interesting and can be safely played for advantage, especially at the amateur level. White gets a wide-open game with lots of piece play, and thanks to his slight initiative can generally get some concession from Black, typically in damaged pawns (following Nxc6) and the two Bishops (if Black plays Bxc3), which makes this a great line for positionally minded players who like to exploit endgame advantages. It is also possible to play for a kingside attack, as demonstrated by Berg - Sokolov, Malmo 2001 and Rasmussen - Jessen, Denmark 2002. The line was employed by many strong players, including:
- Louis Paulsen (see Paulsen - Chigorin, Vienna 1882 and Paulsen - Weiss, Vienna 1882)
- Aaron Nimzovich (see Nimzovich - Leonhardt, Belgium 1907; Nimzovich - Spielmann, Hamburg 1910; and Nimzovich - Rubinstein 1912)
- Rudolf Spielmann (see Spielmann - Nimzovich, Munich 1905; Spielmann-Yates, Semmering 1926; and Spielmann - Lasker, Moscow 1935)
- Moshe Czerniak (see Czerniak-Puiggros, Buenos Aires 1941; Czerniak - Paoli, Venice 1950; and Czerniak - Rellstab, Reggio Emilia 1951)
- Joel Lautier (see Lautier - Campos-Moreno, Manila 1992; Lautier - Karpov, Biel 1992; and Lautier - Sokolov, Correze 1992)
Because the Mieses Variation popularized by Kasparov is all the rage, many books on the Scotch (notably Barsky, Dembo & Palliser, and Wells) skip over the Scotch Four Knights, perhaps on the logic that it is really a variation of the Four Knights Game; meanwhile you will occasionally find good coverage in books on the Four Knights (see especially Pinski's below). But books have become less necessary these days to learning such a popular system, and most players can probably find all that they need on the web. The following bibliography, presented in reverse chronological order, features many online sources which are an ideal starting point.
Scotch Four Knights (C47)
A great Chessgames.com collection on the Scotch Four Knights and related lines (including Belgrade Gambit and 4...Bb4). I often recommend that those seeking to learn a new opening simply play over as many high-level games as possible with the line. Chess.com also has a good page to help you develop your pattern recognition. This is a good place for most players to start, though for more serious students of the game these databases are a bit limited.
An excellent PDF download that is easy to print and covers the whole line for the club player. Argues that "The Scotch Four Knights generally gives a slight edge and almost no losing chances. If you want to exploit small advantages such as the two bishops and better pawn structure in the endgame with little risk, this opening should be considered." Another great opening resource from the excellent Fayetteville Chess Club website.
The Openings Explained: The Scotch Four Knights [C47] by Abby Marshall at ChessCafe (2010)
This is an excellent article, with lots of commentary on minor side-lines that usually escape the notice of analysts but which you're likely to see at the amateur level. Clearly written by a player with lots of scholastic experience playing this line herself.
The Four Knights: Move by Move by Curus Lakdawala (2012)
A useful move-by-move introduction to the Scotch Four Knights by the author of a book by the same title.
C44-C59: Scotch, Four Knights, Italian by various (2010)
A black repertoire in the open games, with the Scotch Four Knights chapter following Svidler - Malaniuk, St. Petersburg 1993-94, which ended quickly after a shocking Svidler blunder.
The Scotch Game (DVD) by Nigel Davies (ChessBase 2009) Running time: 5 hours.
This DVD provides a surprising amount of coverage of the Scotch Four Knights, which Davies recommends as the easiest variation of the Scotch to learn for beginners and amateurs.
Refuting 5...Nxe4 in the Scotch Four Knights by Michael Goeller
Analyzes the game Sevillano - Tamburro, US Open 2007, which offers a very clean and simple way for White to gain the edge against a potentially messy Knight sacrifice. While I still like Sevillano's 7.Be2, White might get a little more edge with 7.f3 as advocated by Abby Marshall and John Emms.
Starting Out: The Scotch Game by John Emms (Everyman 2005), pp. 9-57.
With nearly 50 pages devoted to the Scotch Four Knights, all presented at the amateur level and with no obvious bias for either White or Black, this is probably the book to get if you are looking to limit purchases (especially with so much good material freely available online). Also available as an e-book. Many of the games analyzed are over a decade old, but that is mainly an indication of how little theory has changed in the Scotch Four Knights since the popularization of the Mieses Variation. Main games include Bezman - Varavin 1997, Reinderman - Sokolov 1995, Tzermiadianos - Frendzas 1996, Radulov - Pinter 1978, Oppici - Miotto 1990, Ivanov - Liss 1995, Kobalija - Ivanov 1996, Berg - Leko 1995, Ardelean - Vajda 1999 (see NIC), Krutko - Dzhambulatov 2004, Adla - Muniz 2000, and Miles - Sorin 1995.
The Scotch Game Explained by Gary Lane (Batsford 2005)
Though presented as a repertoire book, this does a great job of covering the whole Scotch. For our purposes, it is especially admirable that the longest chapter in the book is devoted to the Scotch Four Knights Game and offers an excellent overview for amateur players.
The Four Knights by Jan Pinski (Everyman 2003), pp. 40-101.
Good coverage of the line for a general reader without Pinski's usual pro-Black bias. I especially like the quality of the games he chooses, most of which conclude in the endgame stages. Games featured include Bykhovsky - Howell 1995, Kountz - Van den Doel 2000, Nunn - Sulskis 1994, Berg - Sokolov 2001, Pavasovic - Beliavsky 1999, Lutz - Yusupov 1992, Christiansen - Gelfand 1992, and Lautier - Sokolov 1992, Malakhov - Pinter 1995, Golubev - Malaniuk 1994, and Pedersen - Khruschiov 2002.
A Drawing Sacrifice by A.C Van der Tak NIC Yearbook 60 (2001)
Play the Open Games as Black by John Emms (Gambit 2000)
An excellent repertoire book for Black after 1.e4 e5. Emms covers both 5...Bb4 and 5...Bc5!? from the Black perspective.
An Opening Repertoire for the Positional Player by Eduard Gufeld and Nikolai Kalinichenko (Everyman 1998), pp. 27-40.
I have to credit this book for getting me to consider the Scotch Four Knights as a practical weapon for White, though its coverage of the opening is not very deep. I was also influenced by their recommendation of a 2.Nc3 move order to simplify White's preparation.
4.d4 im Vierspringerspiel by Lev Gutman (Erste Auflage 1993)
This book is out of print but is worth tracking down for correspondence players and other serious students as it offers Gutman's typically exhaustive analysis. This volume has an introduction by Victor Korchnoi and focuses on the Scotch Four Knights via a Four Knights move order, dealing with 4...Bb4, the Belgrade Gambit with 5.Nd5, and the Scotch Four Knights.
Winning with the Scotch by Gary Lane (Batsford / Henry Holt 1993), pp. 64-81.
A bit dated but widely available for free download in PDF (not that I advocate that sort of thing). Lane completely redid and vastly improved his presentation for The Scotch Game Explained (see above), greatly expanding his coverage. One advantage of older books like this one, though, is they cover lines that drop out of future discussions, including the crazy 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4 5. Nxd4 Bb4 6. Nxc6 bxc6 7. Bd3 d5 8. e5 Ng4 9. Bf4 d4 10. Qf3 dxc3 11. O-O-O as in Popelyshev - Grischuk, Moscow Open 1995.
New Ideas in the Four Knights by John Nunn (Batsford / Henry Holt 1993), pp. 37-47.
This book is a bit dated and, surprisingly, does not cover the Scotch Four Knights, though it does offer ten pages of analysis on the 4...Bb4 gambit.
Gewinnen mit Schottisch by Lev Gutman (Erste Auflage 1992)
This book is out of print but is worth tracking down for correspondence players and other serious students of the Scotch as it offers Gutman's typically exhaustive analysis. This volume has an introduction by Garry Kasparov and is focused on the Mieses Variation but includes good coverage of early move alternatives, including 4...Qh4, 4...Qf6 and 4...Bc5, important for those using a Scotch move order.
Scotch Four Knights by Alexei Shirov NIC Yearbook 27 (1992)
Scotch Four Knights by René Olthof NIC Yearbook 25 (1992)
An Unbeatable White Repertoire after 1.e4 e5 2.Nf3 by Larry Evans and Ken Smith (Chess Digest 1988)
This book has held up remarkably well despite its age, mostly thanks to the smart recommendations of the late GM Evans. It also offers a good and basic Four Knights repertoire for White. However, while it covers the Belgrade Gambit and 4...Bb4 line, it does not cover the Scotch Four Knights.