Pterodactyl Defense: Austrian, Pteranodon

The Pterodactyl Defense, Austrian and Pteranodon variations, begins with the moves 1.e4 g6 2.d4 Bg7. Here, White intends to control the center by playing e4, which is a strong move that occupies a central square and opens lines for both the queen and bishop to attack. By doing so, White also restricts Black's pawn on g7 and prepares for a quick development of knights and bishops. Additionally, it sets the stage for a tactical game in which both sides will try to control the center and attack the enemy King. In sum, the Pterodactyl Defense can be an excellent choice for players who enjoy aggressive play and creative positions.

When Black responds to 1.e4 with g6, it is known as the Modern Defense or the Pirc Defense. This move prepares to fianchetto the bishop on g7, controlling the diagonal from a7 to g1 and supporting the d6 pawn. This is a flexible and somewhat passive defense that allows Black to not engage in the center right away and instead build a solid position that can be used for counterattacks later in the game. Additionally, the move g6 makes it harder for White to attack the center with their pawns, but leaves the King position exposed to potential attacks from White's pieces. In sum, Black's decision to play g6 reflects a preference for a positional, solid game rather than a tactical one.

After 1.e4 g6, White responds with 2.d4. This move aims to control the center of the board by placing a pawn on d4 and creating a strong pawn chain. By doing so, White also attacks Black's pawn on e5 and prepares to develop their pieces quickly. This move also gives the bishop on c1 an open diagonal to control important central squares. In sum, playing d4 is a natural move for White that solidifies their control over the center and sets the stage for an active and dynamic game. However, it also means that White has to be strategic in their approach to avoid any weaknesses in their pawn structure.

In the Pterodactyl Defense: Austrian, Pteranodon, after the moves 1.e4 g6 2.d4, Black responds with Bg7. This move follows Black's initial plan to fianchetto their bishop and control the important diagonal from a7 to g1. The bishop on g7 also puts pressure on the central pawn chain by attacking the pawn on d4. Moreover, this bishop plays a key role in supporting Black's pawn on e5, which is usually an important outpost for the Black pieces. It is worth noting that by developing the Bishop on g7, Black prepares to castle kingside and avoid any potential attacks from White on the queenside.

After the moves 1.e4 g6 2.d4 Bg7, White's response with f4 aims to control the center while preparing to launch an assault on the Black position. This move supports White's pawn on e5, strengthens the central pawn chain, and frees up the light-squared bishop on c1. By doing so, it also restricts the Knight on g8 from moving to f6, which is a natural square for development. However, this pawn move also has downsides. It weakens the light squares around the White King, and can be exploited by Black's pieces, particularly the Knight on f6, and the Bishop on g7. Therefore, White needs to be careful and consider the potential risks before playing f4.

After the moves 1.e4 g6 2.d4 Bg7 3.f4, Black's response with c5 is a typical move in many hypermodern openings. The move aims to undermine White's central pawn structure by attacking the pawn on d4 and possibly freeing up the c8-bishop through rapid development. By playing this move, Black also gains space on the queenside, which can be used later in the game to launch an attack. However, c5 also has its disadvantages, as it weakens the d5 square, and can potentially give White a central pawn majority in the resulting positions. Therefore, Black often plays carefully and assesses the potential risks of playing c5 before doing so.

In the Pterodactyl Defense: Austrian, Pteranodon, after the moves 1.e4 g6 2.d4 Bg7 3.f4 c5, White's response with c3 aims to control the d4 square and protect the d4-pawn. By doing so, White prevents Black from occupying the central square and gaining a strong pawn chain. Additionally, this move prepares the knight on b1 for development, as c3 supports the idea of a knight on d2, which can then move to f3, putting pressure on Black's center. However, c3 also has its downsides since it weakens the b1-h7 diagonal and can lead to difficulties in the development of the queen's bishop on c1. Therefore, White needs to think carefully before playing c3, taking into account the potential risks and advantages of each move.

After the moves 1.e4 g6 2.d4 Bg7 3.f4 c5 4.c3, Black's response with Qa5 puts pressure on White's pawn on d4. The Queen on a5 attacks the pawn which is already under pressure from Black's pawn on c5. The move also puts pressure on the knight on c3, potentially forcing it to move and further delaying White's development. Additionally, Qa5 develops the queen while avoiding other problematic squares such as d8 or b6, and can be used for tactical ideas later in the game. However, this move also has its downsides. The Queen can be vulnerable to attacks and can be caught out of place or stranded due to the development of other pieces. Therefore, Black needs to be cautious in their approach and ensure the Queen's safety before blindly moving it forward.