Game History

This is the starting position of a chess game. As White, I have the first move. The goal is to control the center, develop pieces actively, and prepare for castling. Several opening moves are common and strong. e4 is a very popular choice, immediately fighting for central control and opening lines for the queen and bishop. d4 is another excellent option, also claiming central space and opening lines. Nf3 develops a knight towards the center and prepares for kingside castling. c4, the English Opening, is a more positional approach, controlling d5. Considering the principles of opening play, e4 is a classical and dynamic move that leads to open games and allows for quick development. It contests the center, opens diagonals for the queen and king's bishop, and is a good starting point for most of White's attacking plans.

The position is the standard opening after 1.e4. White has claimed a central pawn on e4 while Black's pieces are still on their home squares. The key imbalances are: White has a slight lead in development (the e‑pawn is out) and Black’s central pawn is still on d7, ready to contest the centre. Black must choose a plan that keeps the pawn structure sound, develops pieces efficiently, and does not allow White to seize a lasting initiative.

Candidate moves:

• 1...e5: Mirrors White’s central thrust, immediately challenges the e4‑pawn, opens lines for the queen and the f8‑bishop, and prepares natural development (Nf6, Bc5, O‑O). This is the most principled and sound reply.
• 1...c5 (Sicilian): Aggressive and asymmetrical, but it concedes the d5‑square and gives White a tempo to develop the knight to f3 with a comfortable position. It’s a fine choice but less principled at move‑one against a plain e4‑opening.
• 1...e6 (French): Prepares d5 and a solid pawn chain, but blocks the c8‑bishop and yields White a freer development after 2.d4 d5 3.Nc3 or 3.Nd2.
• 1...d5 (Scandinavian): Directly attacks the e4‑pawn, but after 2.exd5 Qxd5 Black’s queen becomes exposed early, and White gains a lead in development.
• 1...Nf6 (Alekhine’s Defence): Attacks the pawn but allows White to advance to e5, gaining space and tempo.
• 1...c6 (Caro‑Kann style) or 1...g6 (modern) are also possible but are less common as a first move after 1.e4.

All lines were examined a few moves deep: after 1...e5 2.Nf3 (the most logical continuation) Black can develop with 2...Nc6, 2...Nf6, or 2...Bc5, each leading to well‑known open‑game theory where Black has equal chances. The alternative replies either give White a clear developmental edge or create early queen exposure.

Given the principle of fighting for the centre, maintaining piece activity, and keeping the pawn structure flexible, the most accurate move is 1...e5.

Thus the best move for Black is:

The opening is standard: 1. e4 e5. White has a central pawn on e4, and Black has mirrored this with a pawn on e5. The position is balanced. The most common and principled move here is to develop a knight to a central square. Nf3 is a strong candidate as it attacks Black's e5 pawn and prepares for kingside castling. Other developing moves like Nc3 or Bc4 are also reasonable, but Nf3 is generally considered the most aggressive and flexible. Let's consider Nf3. If Black defends the pawn with ...Nc6, White can continue development with Nc3 or Bc4. If Black tries to counter-attack with ...d6, White can play d4, opening the center. If Black plays ...Nf6, White can respond with Nxe5, a gambit that can lead to interesting play. Given the lack of immediate threats and the opportunity to develop a piece and put pressure on Black's center, Nf3 is the best move.

The position is a standard Open Game after 1.e4 e5 2.Nf3. Black should develop a piece and control the d4 square. The most natural move is 2...Nc6, putting pressure on the e5 pawn and preparing flexible setups (Italian, Ruy Lopez, Two Knights). It does not create any weaknesses and keeps options open. Other moves like 2...Nf6 (Petrov) are also playable but lead to a different set of lines; 2...Nc6 remains the most popular and versatile choice.

The current position is a standard opening position after 1. e4 e5 2. Nf3 Nc6. Black has defended their e5 pawn with the Nc6. White has several good options, but the most principled move is to develop a piece and contest the center.

Candidate moves:

1. Nc3: Develops the knight and attacks the e4 pawn indirectly. Black can respond with Bb4 (Ruy Lopez), Nf6 (Petrov's Defense if White played Nf3 on move 2, but not here), Bc5 (Italian Game), d6 (Philidor Defense), etc. This is a very common and solid move.
2. Bc4: Develops the bishop and eyes the f7 pawn. This leads to the Italian Game or the Scotch Game depending on Black's response. Common continuations include Bc5 (Giuoco Piano), Nf6 (Two Knights Defense), etc.
3. d4: Immediately challenges the center and opens lines for White's pieces. This leads to the Scotch Game. Black's most common response is exd4.
4. c3: Prepares d4, aiming to build a strong pawn center. This is the preparation for the King's Indian Attack or a delayed Danish Gambit if White plays d4 on the next move.

Analysis:

• Nc3 is a flexible move that keeps options open. It develops a piece and controls central squares. If Black plays Bb4, it leads to Ruy Lopez. If Black plays Bc5, it leads to the Italian Game.
• Bc4 is also a good developing move, aiming directly at Black's weak f7 square. It leads to more tactical positions.
• d4 is the most direct attempt to gain space and activity in the center. It leads to open games.

Considering the options, Nc3 is a sound and flexible developing move that maintains equality and keeps multiple strategic options open. It's a classical approach to developing pieces and controlling the center. It's a good balance between development and central control without committing too early.

Let's evaluate Nc3 further: If 3. Nc3, Black has several good replies:

• 3...Nf6: This is a standard reply, attacking White's e4 pawn. White can respond with 4. d4, transposing to the Scotch Game, or 4. Bb5, leading to variations of the Ruy Lopez or other openings.
• 3...Bc5: This leads to the Italian Game. White can play 4. Bc4 or 4. Nf3.
• 3...d6: This is a more passive move, defending the e5 pawn. White can continue with development like 4. Bc4 or 4. d4.
• 3...Bb4: This leads to the Ruy Lopez. White would play 4. Nf3.

All these continuations are playable and lead to complex games. Nc3 is a safe and principled move.

The position is symmetrical except for the e‑pawns. Black has a developed knight on c6, but the rest of the pieces are still on their back ranks. White has two knights already out, so Black must catch up in development while keeping the centre solid. The pawn on e5 is attacked by the knight on f3, but it is defended by the knight on c6, so White cannot win a pawn by Nxe5. The most principled continuation is to develop the g8‑knight to f6, increasing pressure on e4, preparing kingside castling, and keeping the pawn structure intact. Alternatives such as ...Bb4 or ...d5 are playable but either give White the chance to increase central control (with d4) or leave the bishop on f8 undeveloped. Therefore ...Nf6 is the safest, most flexible move.

The current position is a common opening in the Four Knights Game. White's last move, Nf3, has developed a knight and attacked Black's e5 pawn. Black has responded with Nc6, defending the pawn and developing a knight. White's move 3. Nc3 also develops a knight and supports the e4 pawn. Black's 3...Nf6 develops another knight and attacks White's e4 pawn, leading to the current position. White has several options:

1. d4: This is a very common and principled move in this position, challenging the center and opening lines for White's pieces. It leads to sharp play. If 4...exd4, then 5. Nxd4. If 4...Nxd4, then 5. Qxd4.
2. Bc4: Develops the bishop to an active square, eyeing Black's kingside. This can lead to the Italian Game or Scotch Game structures depending on Black's response.
3. Bb5: This move is part of the Spanish Game, but it's unusual when Black has played 3...Nf6. Black can transpose into a Ruy Lopez if they play 3...a6, but here Black has already played Nf6. A common response would be 4...Nd4, challenging White's knight.
4. g3: A fianchetto setup, preparing Bg2. This is a more positional approach.
5. Be3: Develops the bishop, supporting the d4 square and potentially preparing a queenside attack.

Considering the options:

• d4 seems like the most aggressive and theoretically sound move, directly fighting for the center. It leads to complex middlegames. Black's best response to 4. d4 is usually 4...exd4 or 4...Nxd4.
• Bc4 is also a good developing move, but it might allow Black to equalize more easily if White isn't precise.
• Bb5 is less common here and might lead to tactical complications that White may not be fully prepared for.

I will choose d4 as it is the most principled and creates immediate central tension, forcing Black to make a decision. This aligns with the aggressive spirit of a grandmaster looking to seize the initiative.

The pawn on e5 is under attack by White’s d4‑pawn and also supports White’s centre. If Black ignores it, White can simply play dxe5 winning a pawn. The most direct way to keep equality is to capture on d4, removing the pawn that attacks e5. The move exd4 also opens the d‑file for the queen and keeps Black’s pawn structure sound. After 4...exd4 White will recapture with either Nxd4 or Qxd4, after which Black can continue development with ...Nxd4, ...Bb4 or ...c6 and castle safely. All other moves either lose the e‑pawn or allow White a comfortable central space. Therefore the principled, theoretically sound move is exd4.

The current position arises from the Four Knights Game, Spanish Variation, after Black has just played exd4. White's central pawn on d4 has been exchanged, and the d4 square is now occupied by Black's pawn. White has several options to recapture the pawn or develop pieces.

Candidate moves:

1. Nxd4: This is the most natural recapture. It develops a knight, controls central squares, and maintains symmetry. Black would likely continue developing, perhaps with Be7 or Bb4.
2. Qxd4: This recaptures the pawn with the Queen. While it brings the Queen into play early, it might be vulnerable to attack by Black's developing pieces (e.g., Nc6, Nf6, or a bishop). However, it does centralize the Queen and add pressure.
3. Nd5: This move attacks Black's knight on c6 and centralizes the knight. Black would likely respond with Nxd5 or perhaps a move like c6 to challenge the knight further.
4. Bb5: This develops the bishop and pins the knight on c6 if Black hasn't moved it. However, Black has Nf6, so the pin isn't immediate, but it adds pressure to the c6 knight. Black could respond with a move like c6 or Bd7.

Evaluating Nxd4: If 5. Nxd4, Black can continue developing. For example, 5...Bc5. White might then play 6. Be3, developing and defending the d4 pawn. Or 5...Be7. White could continue with 6. Be3, or 6. Be2.

Evaluating Qxd4: If 5. Qxd4, Black could play 5...Nxd4, which leads to an equal pawn structure but White has lost castling rights if they castle kingside later. Or 5...Bc5, attacking the Queen. White would then have to move the Queen again, potentially losing tempo. For example, 6. Qd3, 6. Qe3, or 6. Qa4.

Evaluating Nd5: If 5. Nd5, Black's knight on c6 is attacked. If 5...Nxd5, White recaptures 6. exd5, opening the e-file and pushing Black's knight away. This gives White a central pawn majority. If 5...d6, White can continue developing with 6. Nxc7+ or simply retreat the knight. If 5...c6, then 6. Nxc6 bxc6 7. dxc6, which gives White a strong central pawn. This looks promising.

Evaluating Bb5: If 5. Bb5, Black could play 5...Bd7, defending. Or 5...a6, challenging the bishop. Or 5...c6.

Comparing moves: Nxd4 is solid and safe. Qxd4 is more aggressive but risks losing tempo. Nd5 looks tactically interesting and potentially leads to a good central pawn structure. Bb5 is also reasonable development.

Let's analyze 5. Nd5 more deeply: 5. Nd5 Nxd5 6. exd5. This opens the e-file and White has a pawn on d5. Black's knight on f6 is still there. Black could play 6...Ne7 or 6...Nb8. White can continue with 7. dxc6 or 7. Be3.

Let's analyze 5. Nxd4 again: 5. Nxd4. This is a very standard move. Black can play 5...Bc5. Then White can play 6. Be3, developing and attacking the bishop. If 6...Bxd4, 7. Bxd4 Nxd4. If 6...Bxe3, 7. fxe3. This seems like a good, solid path.

Considering the tactics and positional advantages, Nd5 appears to be the most aggressive and promising move, potentially leading to a central pawn advantage or tactical complications that favor White. However, Nxd4 is a very safe and principled move that maintains equality and allows for easy development.

After reviewing, Nxd4 is the most common and generally considered best move in this position, leading to a complex but roughly equal game. It recaptures the pawn, develops a piece, and keeps the position solid.

Let's double check 5. Nd5. 5...Nxd5 6. exd5. Black has options like 6...Ne7, 6...Nb8. If 6...Ne7, White can play 7. dxc6 Nxc6 (or 7...bxc6). This looks complicated.

Given the choice between a solid, developing move and a potentially sharp but less explored line, the grandmaster's instinct leans towards the most principled and sound move. Nxd4 develops the knight to a good central square and maintains pawn structure.

Let's reconsider 5. Qxd4. 5...Bc5 6. Qd3. This forces the bishop to move again. 6...Nb4. 7. Qb3. This develops the queen and attacks the knight. Black might play 7...d5. Then 8. Bb5+ c6 9. dxc6 bxc6 10. Ba4. This leads to interesting complications. However, developing the queen early can be risky.

Final decision: Nxd4 is the most solid and principled move, continuing development and recapturing the central pawn. It leads to a standard structure where White has good development prospects.

Black is behind in development and has lost the e‑pawn, so we must seize the initiative. The white knight on d4 is well‑placed, but the black knight on c6 can exchange itself for that knight, after which the black bishop from f8 can develop to c5 with tempo on the white queen. This sequence gives Black rapid piece activity, attacks the queen, and later allows easy development (e.g., ...Bb4, ...0‑0). The exchange does not lose material because White must recapture with the queen, and Black gains a tempo. Therefore the most forcing and principled move is 5...Nxd4.

The current position arises after 1. e4 e5 2. Nf3 Nc6 3. Nc3 Nf6 4. d4 exd4 5. Nxd4 Nxd4. Black has just recaptured on d4 with their Knight, developing it and attacking White's Queen. White's Queen is attacked by the Knight on d4. The most natural move is to recapture the Knight on d4. White's Queen is currently on d1 and the Knight is on d4. Moving the Queen to capture the Knight on d4 is the most forcing and logical move. This develops the Queen and removes Black's active Knight. The alternative is to move the Queen to safety, but that would cede central control and allow Black to maintain a strong central presence with their Knight. Therefore, Qxd4 is the best move, recapturing the pawn and developing the Queen to an active square.

The position is balanced material-wise. Black is slightly behind in development: king on e8, queen on d8, bishops on c8 and f8, knight on f6, rooks on a8 h8. White’s queen on d4 is active and attacks the d7 pawn, but that pawn is well‑defended by the queen, bishop and knight. The most natural way for Black to gain a tempo is to develop a piece while forcing the white queen to move. The move …Bc5 develops the bishop from f8 to an active square, attacks the white queen on d4, and creates threats against f2. After the queen retreats (e.g., Qd3 or Qd1) Black can continue with …0‑0 and later play …d5 or …Be6, reaching a comfortable game with equal material. Other moves like …c5 also attack the queen but do not develop a piece, and …Qd6 or …Nxe4 have no immediate purpose. Therefore the best move is Bc5.

The current position arises after a rapid opening sequence where Black has developed actively, bringing out the queen's bishop and knight. White's queen is currently attacked by Black's bishop on c5. My king is relatively safe for now, but Black's pieces are well-placed and potentially threatening. I need to address the attack on my queen and consider White's development. Several moves are possible for the queen: Qd3, Qe3, Qf4, and Qd2. Moving the queen to d3 or e3 seems reasonable.

Candidate moves for White:

1. Qd3: This defends the bishop on c1, connects the rooks, and keeps the queen active. It also eyes the d5 square.
2. Qe3: This move also saves the queen and prepares for castling. It defends the e2 pawn.
3. Qf4: This is aggressive but might expose the queen too much. It does put pressure on f7.
4. Qd2: A more passive retreat, but keeps the queen safe and might allow for kingside development.

Let's analyze Qd3: If I play Qd3, Black might respond with moves like Bb6, intending to trade bishops or reposition. Or they might continue development with c6 or d6. My queen is safe and my development is on track.

Let's analyze Qe3: If I play Qe3, Black might castle O-O, or play Bb6. This move also prepares O-O for White.

Let's analyze Qf4: If I play Qf4, Black could play Bb6, or even g6 to attack the queen. This seems less optimal than Qd3 or Qe3.

Let's analyze Qd2: If I play Qd2, Black might continue developing with Bb6 or c6.

Comparing Qd3 and Qe3: Qd3 seems to offer more active play and better control of the center. It also keeps the diagonal open for the c1 bishop if needed later. Qe3 is also solid and prepares castling. However, Qd3 feels more dynamic. The bishop on c5 is attacking my queen, so I must move it. Qd3 maintains central influence and prepares for further development.

Therefore, I will play Qd3.

In the current position Black is behind in development: the king is still in the centre, the rook on h8 is inactive and the knight on f6 is the only piece that can be developed further. White’s queen on d3 attacks the d7 pawn, but it is well defended by the queen and bishop. The e4 pawn is defended by the queen, so any immediate capture like ...Nxe4 would simply lose material after Qxe4 and a bishop sacrifice. The safest and most principled plan is to complete development and secure the king. Castling kingside achieves this, puts the rook on f8 on the semi‑open f‑file, and leaves Black ready to play ...d5 or ...Nd5 later while keeping the balance of material. No tactical threats exist for White after ...O‑O, so castling is the best move.

The current position is move 8, White to play. Black has castled kingside and their pieces are relatively developed. The d4 pawn is gone, and White's queen is on d3, slightly exposed but also active. Black's bishop on c5 is well-placed, eyeing the f2 pawn and White's king. White's pieces are also developing, with the knight on c3 and the bishop on b1 yet to move.

My key considerations:

1. King Safety: Black has castled, so their king is safer than mine potentially. My king is on e1, and the bishop on c5 and queen on d3 are potential threats. I need to be mindful of potential discovered attacks or checks if I move the queen.
2. Piece Activity: Black's Nc3 and Bc5 are active. My pieces are developing. The queen on d3 is currently active but could become a target.
3. Pawn Structure: The center pawn structure is open after 4. d4 exd4. White has no central pawns left.
4. Threats: Black's Bc5 is targeting f2 and potentially White's king indirectly. Black's Nf6 is also well-placed.

Candidate Moves:

• Bg5: Develops the bishop, pins the Nf6 to the queen. This seems like a strong positional move. If Black plays h6, I can consider Bxf6 or retreat.
• Bd3: Develops the bishop, potentially supports a later e5 push, and prepares to castle kingside. It also defends the f2 pawn. However, it blocks the d-file for the queen and is slightly passive.
• Be3: Develops the bishop, supports the center, and prepares to castle. It also blocks the queen's access to the d-file.
• Na4: Attacks the Bc5. This could force the bishop back or lead to an exchange. However, Na4 is often a knight on the rim and can be misplaced.
• O-O: Castles the king to safety. This is a standard developing move and important for king safety.

Let's analyze Bg5 more deeply: 8. Bg5

• If Black plays 8...h6, I have 9. Bh4 or 9. Bxf6.
  • 9. Bh4: Black might play g5, attacking the bishop, forcing it to retreat.
  • 9. Bxf6: This exchanges a bishop for a knight, weakening Black's kingside pawn structure and potentially opening lines. If 9...gxf6, then White has a strong attack, but it's a significant commitment.
• If Black plays 8...d6, developing and preparing to challenge the center, this seems reasonable for Black.
• If Black plays 8...c6, preparing to support a d5 push, this also seems solid.
• If Black plays 8...Be7, developing and preparing to castle.

Let's analyze O-O: 8. O-O

• This is a solid developing move, prioritizing king safety. Black would likely continue developing, perhaps with 8...d6 or 8...Re8.
• After 8. O-O, Black could play 8...d6, solidifying the center. Then White might play 9. Re1 or 9. Bg5.
• If 8. O-O, Black could also play 8...b5, expanding on the queenside.

Comparing Bg5 and O-O: Bg5 is more aggressive and directly challenges Black's setup by pinning the knight. It forces Black to react. O-O is more about solidifying my own position. Given that Black has already castled and developed actively, I think it's important to take initiative. The pin on f6 is strong. I will play Bg5.

Black needs to address the pin on the f6‑knight and the pressure on the d7‑pawn. Moving the queen off d8 both defends d7 and removes the pin, while keeping the position solid. The natural ...Qc7 does this, prepares ...Re8 and avoids any immediate tactical threats from White.

Black is currently facing a pin on the f6‑knight caused by White’s bishop on g5. If Black does nothing, White can capture on f6 (Bxf6) and after Black’s queen recaptures, Black would be left down a piece. The most reliable way to neutralize the pin is to interpose a piece between the bishop and the queen. Moving the light‑squared bishop from c5 to e7 both blocks the g5–d8 diagonal and defends the knight, while also developing a piece and connecting the rooks. After …Be7, if White plays Bxf6, Black can simply recapture with Bxf6, resulting in an equal exchange. Other moves (like …Qd7, …h6, or …d6) either allow Bxf6 to win material or do not improve Black’s position as effectively. Therefore the best move is …Be7.

The current position is the result of a Reti Opening transposed into a more mainstream setup. Black has castled and developed their pieces naturally. White has developed their knight and queen, and now needs to continue development. My bishop on g5 is currently pinning Black's knight on f6, which is a key piece for Black's defense and central control. The immediate threats are minimal, but I need to be mindful of Black's potential counterplay.

Candidate moves:

1. Bxf6: This captures the knight, doubling Black's pawns and potentially weakening their king's safety. If Black recaptures with the queen (Qxf6), it activates their queen, but also opens up lines. If Black recaptures with the g-pawn (gxf6), it severely damages their pawn structure and king safety. This looks promising.
2. Bh4: This retreats the bishop, maintaining the pin but potentially losing tempo. It might be a safer option if I'm worried about tactics after Bxf6. However, it feels less ambitious.
3. h3: This move questions the bishop on g5. If Black plays Bxf3, then gxf3 opens the g-file for me. If Black plays h6, it retreats the bishop and potentially loses the pin.
4. O-O: Castling is always a good idea for king safety and connecting the rooks. However, given the pin on f6, I might want to exploit that first.

Let's analyze Bxf6 further: 9. Bxf6 gxf6 (or Qxf6). If 9...gxf6: 10. O-O (or Nd5). The pawn structure is significantly weakened around Black's king. I have good attacking prospects. If 9...Qxf6: 10. Nd5. This attacks the queen and aims to exploit the open lines and potentially the weak f7 pawn. Black's queen is somewhat awkwardly placed.

Considering the options, Bxf6 seems to be the most forcing and promising move to gain an advantage. It directly addresses Black's most active piece and creates structural weaknesses. The alternative of castling doesn't directly improve my position as much as exploiting the pin does. Bh4 is too passive. h3 allows Black to decide the fate of the pin, which I'd rather do myself.

White’s bishop on f6 is attacking Black’s queen on d8 and the bishop on e7. The queen must be saved, so Black has to remove the attacking bishop. The only legal ways are Bxf6 (recapturing with the bishop from e7) or gxf6 (recapturing with the pawn). Capturing with the bishop both eliminates the immediate threat, keeps the bishop pair, and attacks White’s advanced e5‑pawn, giving Black the best activity. Therefore the correct move is Bxf6.

The current position is move 10. White has just completed the opening sequence, with Black having recaptured on f6 with their bishop. Black's bishop on f6 is somewhat passive and blocks the f-pawn. White's queen is well-placed on d3. The main immediate considerations are developing the remaining pieces and improving their position. White's knight on d4 was just captured, and Black's bishop on c5 is no longer a threat to the queen.

Candidate moves:

1. Be3: Develops the bishop, attacks the bishop on c5, and prepares for castling. This seems like a natural developing move.
   • If 10. Be3, Black might respond with 10...Bxe3 11. Qxe3 or 10...Bb6.
     • If 11. Qxe3, White's queen is active and central.
     • If 10...Bb6, White can continue developing.
2. Nf3: Develops the knight, controls central squares, and prepares for castling. This is also a standard developing move.
   • If 10. Nf3, Black might respond with 10...Bg4, pinning the knight. White would then need to consider 11. h3 or 11. Be2.
3. Bc4: Develops the bishop, controls important squares, and targets f7.
   • If 10. Bc4, Black might respond with 10...Bg4, attacking the bishop. White could move the bishop again or consider other options.
4. O-O: Castles the king to safety. This is always a strong consideration.
   • If 10. O-O, Black could continue developing with moves like 10...Re8 or 10...c6.

Evaluating the candidates:

• Be3 seems strong because it develops a piece, gains initiative by attacking the bishop, and prepares to castle. The bishop on f6 is not an active piece for Black, and exchanging it could be beneficial.
• Nf3 is a solid developing move, but Be3 seems more forcing and proactive in this specific position.
• Bc4 might be a bit premature as it can be attacked by Black's pieces.
• O-O is always good, but Be3 develops a piece and puts pressure on Black's bishop first.

Let's analyze Be3 further: 10. Be3. Black's bishop on c5 is attacked. If Black plays 10...Bxe3, then 11. Qxe3. White's queen is centrally placed, and White is ready to castle. If Black plays 10...Bb6, then 11. O-O. White has developed two pieces, castled, and has a better development.

Therefore, Be3 appears to be the most active and beneficial move.