Part I · First steps Chapter 6 of 40
Castling and draws
The only move that moves two pieces at once, and every way to end a game in a draw. We take FIDE's Laws as an arbiter applies them: in disputes at the board.
What to know first: 5 · Check, checkmate and stalemate
What you will learn
- castle and check whether castling is allowed in a position
- recognise a draw by repetition, by the fifty-move rule and in a position where mate is impossible
- understand when running out of time gives a draw, not a loss
White picked up the king on e1 to castle. Black stopped the clocks and called the arbiter: ten moves ago that king had stepped out of check to f1 and then gone back to its own square. White disagrees: the king is on e1 again, the rook on h1 has not moved, and nothing stands between them. Who is right, and what happens to the king that White has already picked up?
An arbiter settles such disputes, and does it by the Laws of Chess of FIDE, the international chess federation: tournaments all over the world are played under them. Here you will be the arbiter. First castling. The first chapter called it the only move that moves two pieces at once, the third called it a special move of the king, and both put off the details until this chapter.
Then draws. The previous chapter noted at the end that stalemate is not the only draw. Besides stalemate, a game ends in a draw by agreement, by repetition of the position, by the fifty-move rule and in a position where mate is impossible. And the rule about running out of time has a proviso that is worth knowing in advance.
Castling: the king moves two squares
In the starting position the king stands in the middle of the first rank, next to the centre. But at the start of a game the centre is cramped and dangerous: pawns and pieces head there, and lines open there. Meanwhile the rook sits in the corner and, as we saw in the second chapter, joins the game last. Castling solves both problems in one move: it takes the king to the edge of the board, behind the pawns, and brings the rook out of the corner.
It is done like this. The king goes two squares along the first rank towards the rook, and the rook jumps over it and lands on the square the king has just crossed. That is castling. Only the knight jumps over pieces, and the rook does it just once, in castling. By FIDE's Laws it is a move of the king, and that will come in handy below.
There are two kinds of castling. Short castling, or kingside castling, goes towards the near rook on h1: the king lands on g1 and the rook on f1. Long castling, or queenside castling, goes towards the far rook on a1. For Black it is all the same, only on the eighth rank. Short castling is written O-O and long castling O-O-O; there is more about the record in chapter 7. On the boards of this course you castle with a move of the king: move it two squares towards the rook, and the rook goes over by itself.
4.O-O: the king has gone from e1 to g1, and the rook has jumped to f1. The king stands behind the pawns on f2, g2 and h2, and the rook is out of the corner.4...Nf6 5.d3 O-O. King on g8, rook on f8.Long castling works by the same rule, only it is further to the rook on a1, and there are three squares between them.
White castles long, O-O-O. Where will the king and the rook end up?
The king goes two squares, e1–d1–c1, and the rook jumps over it onto d1.
A right that is lost for good
Now we can settle the dispute from the start of the chapter. You may castle only if neither the king nor that rook has made a single move in the game. A king that has moved even once loses the right to castle for good, on both sides, even if it later came back to its own square. Black is right, and White is not.
With the rook it is milder. If the rook on h1 has moved, short castling is gone, but long castling with the rook on a1 remains. If a rook has been captured, you will obviously not castle with it any more either. The right is lost by a move, not by how the board looks: a position may be exactly the starting one, but if the king once stepped away and came back, there is no castling in it.
The rook on a1 moved to b1 and went back to a1 after one other move. The king and the rook on h1 have not moved. Which castling moves does White have left?
Only short castling. The rook on a1 lost long castling for good. The king and the rook on h1 have not moved, so the right to castle short is intact: you may castle if nothing in the next section stands in the way right now.
When you cannot castle right now
The king and the rook on their squares are not all it takes. There are four prohibitions that work only at the moment of the move. Once the obstacle goes away, castling is possible again.
- There is a piece between the king and the rook, yours or the opponent's.
- The king is in check: you cannot escape check by castling.
- The king passes through a square that the opponent attacks: f1 in short castling, d1 in long castling.
- The king lands on a square that the opponent attacks, that is, on g1 or c1. You know this rule from the first chapter: a king never steps under attack.
The last three prohibitions concern only the king's own squares: where it stands, which it passes through and where it lands. Let us test them on a position.
White to move. The king and both rooks have not moved. Which castling can White play?
Long castling: the king passes e1–d1–c1, and Black attacks none of those squares. Short castling is forbidden. The bishop on c4 attacks f1, the king would pass through a square under attack, and it does not matter that nothing threatens it on g1. If the bishop leaves that diagonal, short castling comes back.
Check, too, forbids castling only for a while. Parry the check by capturing or blocking, and a king that has not moved in the process keeps its right to castle.
White to move. The bishop on b4 gives check to the king on e1. Can White answer the check by castling?
No. White has four answers to the check: block with the pawn, c3, or move the king to d1, e2 or f1. If White blocks with the pawn, the king stays on e1, and as soon as the check is gone, castling is possible: the king has not moved, so the right is intact.
But some things the rules do not forbid, though beginners often think they do. A rook may stand under attack when you castle with it. In long castling the rook passes through b1, and that square may also be under attack: the king does not go through b1. And if the king was once checked but the check was parried without moving the king, it has not lost the right to castle.
White to move. The rook on a8 attacks the rook on a1, and the bishop on e4 attacks the square b1. Which castling moves are possible?
Both. The rules check only the king's squares: where it stands, which it passes through and where it lands. In long castling those are e1, d1 and c1, and none of them is attacked. It does not matter that the rook on a1 and the square b1 are attacked. Long castling, by the way, takes the rook out of the attack.
Castling can do more than hide the king. In one move it does two jobs: it takes the king off a line and puts a rook on another. Sometimes that is exactly what saves you.
White to move. The rook on e8 attacks the knight on e4, and the knight cannot retreat: behind it on the e-file stands the white king. The knight can be defended only by a pawn, f3, but then Black attacks the knight with a pawn, f5, and it is lost anyway. Find the move that saves it.
O-O-O. The king leaves the e-file, so the knight is free to move, and in the same move the rook lands on d1. If Black now plays 1...Rxe4, then 2.Rd8+ Re8 3.Rxe8#, a back-rank mate, as in the fifth chapter. Short castling is forbidden here: the bishop on c4 attacks f1, the square the king would pass through, and the board will not allow that move. The engine counts every other move as a blunder: the knight is lost.
King first
At a real board every move is made with one hand, and castling has its own order: king first, then rook. This is not a formality. Remember the "touch-move" rule from the first chapter? Castling is a move of the king. If on your turn you touched the rook first, the Laws treat it as a rook move: you can no longer castle with that rook in this move, and you will have to move it.
If you touch the king and then the rook, as you should, you must castle, if castling is legal. And if you touched the king meaning to castle, but castling turns out to be forbidden, you will have to make another move with the king, castling on the other side included, if that is allowed. Only when the king has no move at all may you move any piece.
That is how the dispute from the start of the chapter ends, too. White's king did move once, so castling is impossible, and White touched the king. So White must move the king, with any other king move.
Your move. You have decided to castle short and touched the rook on h1 first. What now?
The rook. By the touch-move rule you must move the piece you touched, and castling starts with the king, so there will be no short castling in this move. This cannot happen on screen: here you castle with a move of the king, and the board moves the rook itself.
Castling that gives mate
In 1912 in London, Edward Lasker (not to be confused with the world champion Emanuel Lasker) played an offhand game with clocks, not a tournament game, against the Briton George Thomas. White gave up the queen, and the black king had to cross the whole board. Look where its walk ended, and where the white king stood all that time.
13.Ng6#, so it steps forward to h6.White to move. Can White castle long here?
18.O-O-O#. The king and the rook have not moved, b1, c1 and d1 are empty, White is not in check, and Black attacks none of e1, d1 and c1. The rook on d1 gives check along the first rank, and the king on g1 has nowhere to go: f1 is attacked by the rook and the bishop on e2, h1 and g2 by the rook on h2, the pawn on f2 is defended by that same rook, and the rook on h2 by the knight on g4. There is nothing to capture the rook or to block with.
Lasker himself played 18.Kd2#: the king left e1 and opened the first rank to the rook on a1, and the rook gave the mate. Long castling would have given the same mate, only with the rook on d1. Lasker later wrote that he saw castling too, but chose a move with one piece.
Half a point: how a game ends in a draw
A game that nobody won is a draw. In a tournament each player gets half a point, and the record says ½-½, as you saw in the fifth chapter. You already know one draw: stalemate. The others, apart from agreement, come in two kinds. Some are automatic, like stalemate: the game ends that second, and nobody needs to claim anything. Others must be claimed: the player on the move turns to the arbiter, who checks, and if the claim is correct, the game is over.
| Draw | How it happens |
|---|---|
| Stalemate | automatic |
| Agreement | when both agree |
| Dead position | automatic |
| Threefold repetition | on claim |
| 50 moves | on claim |
| Fivefold repetition | automatic |
| 75 moves | automatic |
Do not claim a draw at random. If the arbiter finds the claim incorrect, the game goes on, and two minutes are added to the opponent's clock.
By agreement
This is the commonest way. One player offers a draw, the other accepts, and the game is over. The only condition is that each player has made at least one move.
You offer a draw on your own turn: first make your move on the board, then say "I offer a draw", and only then press the clock. That way the opponent thinks about the offer while their own clock is running. An offer cannot be withdrawn, and no conditions may be attached to it. It stands until the opponent accepts it, declines it aloud, or touches a piece with the intention of moving it. On the scoresheet, the sheet on which the players write down the moves of the game, an offer is marked with the sign (=); how to keep the record is explained in chapter 7.
Some tournaments forbid draws by agreement before a certain move, or altogether, so that players do not split the point without playing a game. The Laws allow this, and the ban itself goes in the tournament regulations.
How do the Laws say to offer a draw?
First the move on the board, then the offer, then the clock. That way the opponent gets both your move and the offer at once, and thinks about them while their own clock is running.
Repetition
If the same position has appeared on the board for the third time, the player on the move may claim a draw. This is threefold repetition. The same moves do not have to be repeated: the position may return by another route, and after many moves.
Most often repetition comes from perpetual check. One side gives check on every move, the other gets out of it but cannot escape the checks for good, and the positions begin to repeat. The rampaging rook in the Evans v Reshevsky game from the fifth chapter threatened exactly this. Perpetual check saves even those who have almost nothing left. Find one yourself.
White to move. Black has an extra rook (for two pawns) and threatens Rb1: the rook would attack the queen, with the king behind it. Find the move that saves the game.
Qe8+. The king on g8 has one square left, h7: f8 and h8 are on the queen's line, and the queen attacks f7 along the diagonal. Then Qh5+, and the king can only go back to g8: the queen attacks g6, and h6 and h8 lie on its file. There is nothing to block with. The checks will repeat until the position appears for the third time. Any other move by White loses.
1.Qe8+ has appeared for the first time. Black to move, with one move: Kh7.Notice who claims. The position appeared for the third time after White's move, and the player now on the move may claim: Black. White could have claimed the draw too, a move earlier. For that you do not play the move on the board but write it on your scoresheet, tell the arbiter that this move will bring about the same position for the third time, and claim the draw. A move that has been written down cannot be changed.
What does "the same position" mean? It is not enough for the pieces to stand on the same squares. The same side must be on the move, and both sides must have the same possibilities, including the same rights to castle and the same right to capture en passant. A position in which the king can still castle and the same arrangement in which it no longer can are different positions. Here is how that looks in a deliberately silly game.
1.e4 e5. Both kings still keep the right to castle on both sides.And if nobody claimed a draw and the position has appeared for the fifth time, the draw comes automatically, with no claim at all: the arbiter watches for it.
Fifty moves
If each side has made fifty moves in a row and in all that time there has been no capture and no pawn move, the player on the move may claim a draw. This is the fifty-move rule. As with repetition, you may claim a move earlier: write down the move after which fifty moves will be reached, and declare it to the arbiter.
The count starts again after every capture and every pawn move. Those are moves that cannot be undone: a pawn does not go back, and a captured piece cannot be returned to the board. If there are no such moves for fifty moves in a row, then in all likelihood nobody can move the game forward, and the rule does not let it be dragged out without end. The mates against a lone king that chapter 9 covers fit into this limit with room to spare. Even the hard mate with bishop and knight takes no more than 33 moves.
And if nobody claimed a draw, and each side has made 75 moves without a capture or a pawn move, the draw comes automatically. There is one exception: if the last of those moves delivered mate, the mate takes precedence.
For forty-nine moves in a row nobody has captured or moved a pawn. Which moves start the count of fifty moves from the beginning? There are two correct answers, and either will do.
Only two kinds of move reset the count: a capture and a pawn move, promotion and capture en passant included. Checks, castling, king moves and piece moves without a capture do not stop it.
When mate is impossible
Sometimes nobody can give mate, however both sides play, even if one of them deliberately helped the other. Such a position is called a dead position, and the game is drawn at once, as soon as it appears on the board. Nobody needs to claim anything.
Most often this happens when almost nothing is left on the board. King against king. King and bishop against king. King and knight against king: you saw this case in the third chapter. And king and bishop against king and bishop, if both bishops move on squares of the same colour (light-squared or dark-squared). Such draws are often called insufficient material.
But if the bishops are of different colours, mate exists. It needs help from the losing side: its own bishop covers the king's last square.
The arbiter does not care whether the stronger side can win against the best defence. All that matters is whether there is any path to mate at all, even if the opponent drives their own king into the corner. If there is a path, the game goes on.
In which of these positions does the game end in a draw at once, as soon as it appears on the board?
A king and a knight cannot give mate, even if the opponent helps. In all the other cases mate is at least possible, and the game goes on.
With two knights it is subtler. Mate with them exists, and here it is:
So the position is not dead, and the game goes on. But you cannot force the opponent into such a mate. The king does not have to go into the corner, and at the right moment it always has another move. The endgame tablebases the course's engine plays by confirm this: two knights against a lone king is a draw if the defender does not make a mistake. A mistake is possible, though.
Black to move. The knight on f6 gives check to the king on g8, and the king has two squares. Where should it go to avoid mate?
Kf8: the king moves away from the corner, and there is no mate. After Kh8 White mates at once: the knight on e5 jumps to f7, and you get the position from the diagram above. The whole secret of the defence is one thing: do not walk into a spot where one knight move is enough.
So how does such a game end? By agreement, by repetition or by the fifty-move rule: you now know all three.
A position can also be dead with many pawns on the board. Here there are sixteen, and mate is still impossible.
Here you need neither to count material nor to look for moves: it is enough to see that nothing on the board will ever change. The kings could shuffle back and forth behind their walls without end, but there is no need to play on: the game was drawn at the moment the position appeared on the board. If the players do not notice, the arbiter will declare the draw.
The flag falls
In a game with a clock each player has their own supply of time. Whoever fails to make the required number of moves in time loses. The first chapter said so briefly. On the old mechanical clocks a little flag fell at that moment, and people still say "the flag falls".
But here too there is a proviso. If the opponent cannot give mate by any possible series of legal moves, even with your help, running out of time brings a draw, not a loss. You have a queen against a lone king, and it is you who have run out of time: a draw, since the opponent cannot give mate with a king alone. And if the game has already ended earlier, by mate, stalemate, agreement or a dead position, a flag that falls afterwards changes nothing.
The same proviso applies to resignation. If the opponent cannot give mate by any possible series of legal moves, you cannot resign: the game is drawn anyway.
The rule is short but exact to the letter: "by any possible series of legal moves". Test yourself.
A game with a clock. Black has run out of time. How did the game end?
White won. Mate with the knight is possible if the black king stands in the corner on a1 and its own pawn on a2 covers its last square. It does not matter that Black will never play like that: the rule asks only whether there is any path to mate at all.
For the same reason, a player with a lone king against two knights loses if it is their time that runs out: mate with two knights exists. Against two knights you are saved by the board, not by the clock.
What's next
Now you know all the rules of the game, from a pawn move to a fallen flag, and can settle any dispute at the board. But to prove threefold repetition to an arbiter, or to count fifty moves, you need a record of the game: the arbiter looks at the scoresheet, not at the players' memories. How moves are written down, O-O and O-O-O included, and how to read games in books and in PGN, is explained in chapter 7. And how to give mate to a lone king with a queen or a rook within fifty moves, without stalemating, is taught in chapter 9.