Ruy Lopez: Berlin Defense, Rio Gambit Accepted

In the Ruy Lopez: Berlin Defense, Rio Gambit Accepted, white plays e4 as their second move. This move aims to gain control over the center of the board and allows white to develop their bishop on the next move with a threat to the black knight. By controlling the center, white can dictate the pace of the game and limit black's freedom of movement. The move e4 is an assertive start to the game and sets the stage for an aggressive attacking style of play.

Black wants to play e5 to challenge white's control over the center of the board. This move helps black to establish their own pawn chain, with pawns on e5 and d6. By placing their pawns on these squares, black can defend their position and limit white's chances to attack. The move e5 also frees black's dark-squared bishop and allows it to develop. This move is a common response to white's e4 and aims to equalize the position by creating symmetrical pawn structure.

White plays Nf3 to develop their knight and control the central squares of the board. Nf3 also prepares for the potential fork on e5 if Black decides to advance their pawn. Additionally, Nf3 supports the pawn on e4, making it easier to defend. This move is very common and flexible for White, as it can also lead to many different openings. Nf3 also sets up potential threats for Black, such as Ng5 or Nc3 to attack the f7 square. The move Nf3 is an important step in white's opening strategy to develop their pieces and gain control of the center.

In the Ruy Lopez: Berlin Defense, Rio Gambit Accepted, Black plays Nc6 after white's move Nf3. This move develops Black's knight and prepares to attack the pawn on white's e4. Additionally, Nc6 controls the central squares of d4 and e5, making it easier for Black to contest for control over the center. By developing the knight on c6, Black also clears the way for advancing their d-pawn to d5, gaining more space and control over the center. Nc6 is a common move that helps Black's development and sets up potential threats against White's central pawn.

White plays Bb5 in order to control the center and put pressure on the black knight on c6. Bb5 also pins the knight to Black's king, preventing them from playing the pawn move ...d6 to control the center. This move is a common tactic in many openings and can often lead to White gaining a temporary advantage. Additionally, Bb5 sets up potential trades of the bishop for the knight, which could weaken Black's pawn structure or give White a lead in development. The move Bb5 is an important step in White's opening strategy to gain control of the center and increase the pressure on Black's position.

In response to the move Bb5, Black plays Nf6 with the aim of attacking the bishop and gaining control of the center. Additionally, Nf6 develops a piece and puts pressure on white's pawn on e4. The move Nf6 can also prepare Black for the pawn move ...d6, which can help control the center and protect their king. This move also sets up the possibility of playing ...g6 and ...Bg7 to fianchetto the dark-squared bishop. Nf6 is an important move in Black's opening strategy to gain control of the center and limit White's attacking options.

In the Ruy Lopez: Berlin Defense, Rio Gambit Accepted, White plays O-O to castle their king to safety and connect their rooks. This move also moves the king to a safer position on the kingside, further away from the center and potential attacks. O-O is an important move in many openings, as it allows White to mobilize their pieces and prepare for the middle-game. The move also increases the pressure on Black's position, forcing them to quickly complete their own development and prepare counterattacks. O-O is a common move that signals the start of the middle-game and sets the stage for more complex strategic play.

In response to O-O, Black plays Nxe4 to capture White's pawn and gain an advantage in material. This move is also a common sacrifice in the Ruy Lopez opening, as it can create weaknesses in White's position and slow down their development. Black's attack on the pawn also exposes White's king, which could create tactical opportunities for Black in the future. Nxe4 is a dynamic move that aims to disrupt White's plans and gain an early advantage. However, this move does come with risks, as Black's knight could become vulnerable to attacks if not protected properly.