I occasionally play the Open Game as Black, often transposing from the Nimzovich after 1.e4 Nc6 2.Nf3 e5 when I don't feel like playing the 2...d6 lines. When I play 2...e5 it's usually because I'm expecting a Ruy Lopez, since I have a few specialized lines against the Spanish that I enjoy torturing White with. Almost invariably, though, I find myself instead on the Black side of the Two Knights Defense. Fortunately, I am fairly booked up on this since there is a lot of analysis out there for those who are looking. A few new things for players of the Two Knights as Black have recently appeared and so I thought a bibliography update was in order.
The most recent online contribution to the Two Knights is Pete Tamburro's excellent lecture on the Fritz Variation in the Two Knights at Chess.fm, to which he promises a sequel. He has also posted some notes at his excellent "Openings for Amateurs" message board. It is interesting how much recent attention is being given to the Fritz, and Pete's lecture and his notes make for a wonderful introduction to anyone unfamiliar with these lines -- or, as Pete suggests, for players who think the only fun thing to play against 1.e4 is the Sicilian. These lectures are posted on a rotating schedule and then disappear for a while, so be sure to catch this one soon.
The other recent online piece, to which there is also a promised sequel, is Tim Harding's excellent "Open Games Revisited: The Two Knights" at Chess Cafe. He has written several other useful things on these lines (see list below), but the latest provides a fresh perspective by focusing on the Fritz and lines other than the classical 5....Na5 (which was the focus of his previous series). Be sure to check The Kibitzer column again in early December for the sequel.
If you enjoy these pieces on the Fritz variation, then I suggest you definitely download Having Fun with the Two Knights Defense by Bobby Ang from the web archives. It is definitely a lot of fun and was the first thing I had read to make me seriously consider the Black alternatives to 5...Na5 in the main line. After reading the articles above, I now want to return to it and think about the Fritz some more!
There is also a very recent book by Nigel Davies (Play 1.e4 e5!) which disappoints because most of it is devoted to a specific and boring variation against the Ruy Lopez. Its Two Knights Defense coverage is also not that great and generally repeats the same lines as John Emms offers. Among recent books, in fact, I think that only Jan Pinski offers anything of value on the Fritz. And only Emms's book is a must-have (but it does not do the Fritz). It's too bad that Davies has not offered something more innovative. This is one place where the web sources have actually surpassed those in print!
There are a few available books, which I give in alphabetical order. Other than Emms and Pinski, though, I'd stick to web sources unless you are the type who just has to have everything!
Acers, Jude and George S. Laven. The Italian Gambit System. Trafford Publishing, 2003.
Gives relatively recent coverage of practically every line in the Open Two Knights (with White d4). Does offer some useful insights on the 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4 lines. All from White's perspective.
Baker, Chris. A Startling Chess Opening Repertoire. London: Everyman Chess, 1998.
Useful (if overly selective) coverage of the 5.O-O Nxe4 lines in a repertoire book built around the Max Lange Attack and Koltanowski Gambit all from the White perspective.
Beliavsky, Alexander and Adrian Mikhalchishin. The Two Knights Defense. London: Batsford, 1999. Very poorly put together book (seems rushed to the publisher) with occasionally strong moments. Focuses exclusively on the 5...Na5 lines against 4.Ng5. Very lame.
Davies, Nigel. Play 1.e4 e5! Everyman Chess 2005.
Hot off the press but rather a disappointment, frankly. I like Davies's work generally, but over half the book is devoted to the intricate Keres Variation of the Ruy Lopez (with 1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O Be7 6.Re1 b5 7.Bb3 d6 8.c3 O-O 9.h3 Na5 10.Bc2 c5 11.d4 Nd7) which bores me to tears. And the coverage of the Two Knights follows John Emms a bit too closely to be of great value, including 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4 or 5.e5 Ne4!? or 4.Ng5 d5 5.exd5 Na5. The games are recent but this is not exciting. If you are looking for a good anti-Lopez weapon, I recommend Larry Kaufman's The Chess Advantage in Black and White which covers the Berlin Defense beautifully.
Emms, John. Play the Open Games as Black: What to Do When White Avoids the Ruy Lopez. London: Gambit, 2000. Excellent coverage of the Two Knights lines from the Black perspective, but focuses exclusively on 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.d4 exd4 5.O-O Nxe4 and 5.e5 d5 or 5.e5 Ne4!? or 4.Ng5 d5 5.exd5 Na5. This is a classic that should be on the shelf of anyone who plays 1.e4 e5 as Black or White.
Estrin, Yakov. The Two Knights Defense. Trans. K. P. Neat. London: Batsford 1983. There are various versions in multiple languages and editions of Estrin's work. Estrin's analysis became widely circulated in multiple editions and languages through the 70s and 80s. It is still vital and valuable, especially since some lines he discusses receive scant treatment later.
Harding, Tim. The Evans Gambit and a System versus the Two Knights Defense. Second Edition. Chess Digest, 1996. A very useful if selective repertoire coverage of the Modern d4/e5 lines of the Two Knights exclusively from the White perspective.
Nunn, John. Secrets of Grandmaster Chess. 1997. pp.77-87.
Discusses the game Corden-Nunn, Birmingham 1975 in great depth.
Petrosian, Tigran and Yakov Estrin. Zweispringerspiel im Nachzuge. Hamburg 1966.
Pinski, Jan. The Two Knights Defense. London: Everyman Chess, 2003.
Probably the most generally useful current book available. The analysis is generally shallow but the coverage is very wide and generally good.
Soltis, Andrew. Winning with the Giuoco Piano and the Max Lange Attack. 2nd Revised Edition. Chess Digest, 1996 (1st edition 1992). Offers some surprising analysis of the Max Lange lines, though I wonder how well it holds up to close scrutiny since it does seem overly optimistic. Guess whose side he's on....
Van der Tak, A. C. and Jesus Nogueiras. "King's Pawn Opening: Max Lange Attack." New in Chess Yearbook 37 (1995): 94-99. One of a number of articles to appear in New in Chess and NIC Yearbook. See their website for details.
Zagorovsky, Vladimir. Romantic Chess Openings. London: Batsford 1982. A classic, if now generally out of date and shallow.
I have posted a previous entry on the Modern Variation which you might also want to see. There are lots of good things online, and if you are mostly interested in the Fritz variation you would probably do best to save your money and just check out some of these links!
E5/E5 Defenders by Pete Tamburro at Chess.fm
Open Games Revisited: The Two Knights by Tim Harding at Chess Cafe
The Main Line of the Two Knights Defense by Mark Morss
Excellent coverage of 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 lines from Black's perspective. Be sure to scroll down and click the links to his two games. One of the best pieces you can read if you are interested in these lines.
Two Knights Defense by Tim Harding
In three parts, covering the classic 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5.
Part One, Part Two, and Part Three.
Two Knights -- Amazing Counter-Attack by Tim Harding
Covers 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Nxe4!? which is fun for speed chess.
Having Fun with the Two Knights Defense by Bobby Ang
Some really spectacular analysis of the Fritz with ...Nd4 -- the same line discussed by Pete Tamburro at Chess.fm.
Defensa de los Dos Caballos from Hechiceros
Focuses on 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5.
Opening Lanes #62 by Gary Lane
Discusses 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 d5 5.exd5 Na5. For the line 6.Bb5+ c6 7.dxc6 bxc6 8.Qf3!? see Opening Lanes #02. For 6.Bb5+ Bd7!? see Opening Lanes #03.
Two Knights Defense, Wilkes-Barre Variation
1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5 Bc5 5.Bxf7+ Ke7 and 6.Bd5 . See also the 6.Bb3 Line.
Site dedie a l'ouverture Traxler
A whole website devoted to the Traxler. In French with lots of Traxler stuff from the Black perspective.
"Opening Preparation" by Sunil Weeramantry at Chess Cafe's Archive. See "The Chess Coach" #13. Download a zip file. Discusses the Two Knights Modern for White with Black's cooperative 5...d5.
There had been a sample article on the Traxler at the New in Chess Yearbook site, but it has since gone missing. NIC Yearbook also has had some articles over the years which I have not represented very well above because they are not handy. I may return here and add them.