The Hyperaccelerated Pterodactyl, Exchange Variation is a variation of the Sicilian Defense, catalogued as ECO B27. The line runs 1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+ 5. Nc3 Bxc3+ 6. bxc3 Qxc3+, reaching the position shown below after 12 half-moves.
White holds the centre with pawns on e4. Development is level at two minor pieces each. It is White to move after six moves. White has doubled pawns on the c-file; White’s c- and a-files pawns are isolated; White has the bishop pair.
On the Sicilian Defense generally: The most popular and aggressive response to 1.e4. Black fights for the center asymmetrically, leading to rich tactical play.
You can play through this variation move by move in your browser — Learn mode walks the line with an explanation at each step, and Drill mode replays it from memory so you find out whether you actually know it. No account is required.
See all 238 Sicilian Defense variations →
The Hyperaccelerated Pterodactyl, Exchange Variation goes 1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+ 5. Nc3 Bxc3+ 6. bxc3 Qxc3+. It is a variation of the Sicilian Defense and is catalogued as ECO B27.
The Hyperaccelerated Pterodactyl, Exchange Variation is ECO B27. ECO codes group openings by their move order, so nearby codes cover closely related lines of the Sicilian Defense.
Stockfish evaluates the position after 1. e4 c5 2. Nf3 g6 3. d4 Bg7 4. dxc5 Qa5+ 5. Nc3 Bxc3+ 6. bxc3 Qxc3+ at +0.09 at depth 18, which is balanced. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
White holds the centre with pawns on e4. Development is level at two minor pieces each. It is White to move. White has doubled pawns on the c-file; White’s c- and a-files pawns are isolated; White has the bishop pair.