Modern Defense: Pterodactyl & Semi-Averbakh Variation

Modern Defense

Definition

The Modern Defense is a hyper-modern chess opening that begins with the flexible fianchetto 1…g6 against either 1.e4 or 1.d4. Black allows White to occupy the center with pawns, planning to undermine and attack it later with pawn thrusts such as …d6, …c5 or …e5, and with piece pressure along the long a1–h8 diagonal.

Typical Move Orders & Key Ideas

Against 1.e4 the most direct sequence is:
resulting in a position where:

Black’s dark-squared bishop exerts long-range pressure from g7.
…d6 and …c6 (or …c5) support a later …e5 break or a …c5 lever, striking at the center.
Black often keeps the king un-castled for a while, reserving the option of castling queenside if the position warrants it.

Strategic Themes

Hyper-modern counter-punching: ceding space early in order to destroy the center later.
Dark-square control: The g7-bishop and moves like …c5 or …e5 aim at d4 and e4.
Flexibility: Black can transpose to the Pirc Defense with …Nf6 and …d6, to the Robatsch line with …c5, or even to certain Benoni-style structures versus 1.d4.

Historical Significance

The opening was popularized after World War II by players such as Grandmaster Aleksandar Matanović and Swedish GM Gideon Ståhlberg, but its real champion was the Austrian IM Karl Robatsch in the 1960-70s, when it was frequently called the “Robatsch Defense.” The name “Modern Defense” gained traction in English-language literature in the 1970s to emphasize its hyper-modern roots.

Illustrative Games

Bent Larsen – Bobby Fischer, Portorož 1958 (1.e4 g6 2.d4 Bg7 3.Nc3 d6 …) – Fischer successfully equalized and drew against one of the world’s sharpest attackers.
Nikola Sedlak – Magnus Carlsen, Internet Blitz 2021 – Carlsen used a Modern move order to reach a Pirc-type middlegame and outplayed his opponent in a complex endgame.

Interesting Facts

The Modern is one of the few 1…g6 openings that can be played almost regardless of White’s first move, making it attractive for “system” players.
Because Black’s queen often lands on a5 in several sub-lines, some early writers nicknamed these setups the “Queen’s‐Side Modern.”

Pterodactyl Variation (Modern Defense)

Definition

The Pterodactyl Variation is an aggressive branch of the Modern Defense in which Black combines a king-side fianchetto with an early …Qa5, visually “swooping” across the board like the prehistoric flying reptile for which it is named.

Characteristic Position

Typical move order (the “Sicilian Pterodactyl”): 1.e4 g6 2.d4 Bg7 3.Nc3 c5 4.dxc5 Qa5+. An alternative “Pirc-Pterodactyl” starts 1.e4 g6 2.d4 Bg7 3.Nf3 d6 4.Nc3 c5 5.dxc5 Qa5.

Strategic & Tactical Motifs

Early queen harassment: …Qa5 puts immediate pressure on c3 and e1, often forcing awkward concessions from White.
Unbalanced pawn structure: Black is willing to sacrifice central pawns (…c5) in return for rapid development and diagonal pressure.
Mixed tactical themes: Ideas like …Bxc3+ double White’s pawns, while …Qxc5 recaptures the pawn and keeps material balance.

History & Popularity

The variation was christened the “Pterodactyl” in the 1980s by American theoretician FM Eric Schiller, who was fascinated by its adventurous spirit. Although rarely seen at elite level, it enjoys a devoted following among club players looking to sidestep main-line theory.

Notable Example

Sergei Rublevsky – Daniel Gormally, European Team Ch. 2005: Rublevsky calmly neutralized the queen excursion and transitioned into a stable extra-pawn ending, illustrating both the risk and reward of Black’s concept.

Fun Facts

Some offbeat aficionados collect “dinosaur openings” – the Pterodactyl, the Velociraptor (a Scotch sideline), and the Stegosaurus (a Caro-Kann rarity).
ChessBase once ran a theme tournament called “Jurassic Park” limited to Pterodactyl positions.

Semi Averbakh Variation (King’s Indian Defense)

Definition

The Semi-Averbakh Variation is a branch of the King’s Indian Defense in which White develops the bishop to g5 before playing Nc3, delaying the commitment of the c-knight and thus retaining extra flexibility. A common move order is: 1.d4 Nf6 2.c4 g6 3.Nf3 Bg7 4.Bg5.

Difference from the Full Averbakh

Averbakh Proper: 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Bg5.
Semi-Averbakh: White withholds both Nc3 and e4, making it harder for Black to choose the optimal pawn break (…c5, …e5 or …d5).

Main Ideas for Each Side

White:

Pin the f6-knight, discouraging the thematic …e5 break.
Keep the c-pawn mobile (c2-c4-c5) to seize queenside space.
Decide later whether to play e2-e4 (transposing to regular Averbakh) or opt for a quieter Queen’s Gambit-style setup.

Black:

Challenge the pin with …h6 and …g5, or via the maneuver …Na6–c5 attacking d3 and e4 squares.
Consider an immediate central strike …d5, taking advantage of the fact that White’s knight is not yet on c3.
Maintain typical King’s Indian piece play: …Nbd7, …e5, …c6, then storm the kingside if allowed.

Historical Background

Named after Soviet GM and theoretician Yuri Averbakh, the original line appealed to positional players who wanted to blunt Black’s kingside attack. The “Semi” version gained traction in the late 1990s, employed by players like Peter Svidler and Vishy Anand as a practical anti-King’s Indian weapon with a smaller theoretical burden.

Illustrative Game

Vishy Anand – Garry Kasparov, Wijk aan Zee 1998. Anand obtained a small but nagging edge and eventually won a textbook minor-piece endgame, showcasing the Semi-Averbakh’s potential for long-term pressure.

Interesting Tidbits

The early bishop sortie to g5 can transpose to Trompowsky-style positions if Black answers 3…d5 instead of 3…g6.
Because the move order is so elastic, databases label the same position under ECO codes A48, E70, and even D90 depending on transpositions.