Paris, autumn 1858. Paul Morphy (White) v. the Duke of Brunswick and Count Isouard (Black, consulting). Philidor Defence. 1–0, 17 moves.

Document 1. What we know, and how

Every move below is the standard score, and every move was replayed by code before this page was published: each is legal, each check is a check, and the last move is mate. The score is held in the ClassicsForge bank on this site, which is the authority if any copy disagrees.

What we do not know is the night. Edward Winter's review of the contemporary evidence in Chess Notes gives two candidates: Norma, in late October, or, most probably, The Barber of Seville, on 4 November 1858. It is one of the most reprinted short games in chess. The evening it was played in is still argued about. Hold those two facts together; it is a useful habit.

Document 2. The score, with notes

1. e4 e5 2. Nf3 d6. Philidor's Defence, solid and a little passive. Black commits to defending e5 with a pawn rather than a piece.

3. d4 Bg4. The first decision worth arguing about. Black pins the f3 knight to the queen before developing a single kingside piece. A pin is a claim on the future: it is worth something only if you can maintain it. Here Black cannot, and the next move shows it.

4. dxe5 Bxf3. Forced, more or less. After 4...dxe5 5. Qxd8+ Kxd8 6. Nxe5, Black has lost a pawn and the right to castle in one sequence. So Black spends the pinning bishop to keep the structure. The pin lasted one move and cost a minor piece's worth of time.

5. Qxf3 dxe5 6. Bc4. White now has two pieces developed and an open diagonal to f7. Black has none developed. Count that, not material: the position is level on the board and already uncomfortable for Black.

6... Nf6 7. Qb3. The double attack. The queen hits b7 directly and f7 from behind the c4 bishop. Black can cover one.

7... Qe7. Covers f7 and gives up b7. It also parks the queen in front of the f8 bishop, which will never move again. Note it now; it is the end of the game in miniature.

8. Nc3 c6 9. Bg5. The famous refusal. 9. Qxb7 wins a pawn, and Black answers 9...Qb4, offering the queens; if they come off, White is a pawn up in an endgame and the attack is over. Morphy plays for the initiative instead: Bg5 pins the f6 knight to the queen, and Black cannot easily break it, because Black has nothing else in play.

9... b5. Black tries to drive the bishop from c4 and close lines.

10. Nxb5! cxb5 11. Bxb5+ Nbd7. The knight is given to open the b5–e8 diagonal. Black's interposition creates a second pin, this one absolute: the d7 knight cannot legally move.

12. O-O-O. One move, two jobs: the king leaves the centre, the rook arrives on the open d-file aimed at the pinned knight.

12... Rd8 13. Rxd7! Rxd7 14. Rd1. The point of the order. If the bishop took on d7, the pin would be spent. Taking with the rook keeps the b5 bishop's pin in force, now on the recapturing rook, while the second rook doubles behind. Attackers on d7: two. Defenders: the queen, and the f6 knight, which is itself pinned to the queen. The attack is arriving while the pins hold.

14... Qe6. Unpinning the f6 knight by moving the queen off the g5–e7–d8 line, and offering a queen trade on b3.

15. Bxd7+ Nxd7 16. Qb8+! The deflection. The queen is given away so that the d7 knight, the one piece blocking the d-file, must leave it.

16... Nxb8 17. Rd8#. Mate by the last rook, covered by the last bishop. Check the escape squares yourself: d7 and d8 are the rook's, e7 is the g5 bishop's, f7 and f8 are Black's own pawn and bishop.

Document 3. The count that matters

At the final position, Black's f8 bishop and h8 rook have never moved. White has given up two knights, a bishop, a rook and the queen; White has a rook and a bishop left, and they are enough. A useful way to state the lesson is not "development matters", which everyone knows, but this: in an open position, a piece not yet in play is worth less than its material value, and a pin is worth exactly as much as your ability to keep it.

Try putting a number on it. At the start of move fifteen Black has a queen, two rooks, a bishop and a knight; White has a queen, a rook and two bishops. Even counting White's two extra pawns, Black is ahead by the usual piece values. Yet the game ends three moves later. The usual values assume a piece can join the game when it is needed. The h8 rook cannot move at all until the king does, and the f8 bishop would need moves Black does not have time for. A piece that cannot arrive in time is, for the purposes of the next three moves, not on the board at all.

Document 4. The objections

Two honest objections belong next to the praise.

First, Morphy's opponents were amateurs consulting in a theatre box. The game shows a principle beautifully, but it is not evidence of how strong players defend. Modern annotators point to better defensive tries for Black at several points; none of them changes the verdict that Black's development was too slow.

Second, the game is famous partly because it is short, clean and teachable. That is a selection effect. Many of Morphy's games against stronger players are longer and less tidy. A collection made of perfect miniatures teaches the principle and hides the struggle.

Neither objection makes the game less instructive. Both make it more honest. A lesson that comes with its own limits printed beside it is one you can trust a little further.

Document 5. Two kinds of pin

The game turns on a distinction worth stating precisely, because textbooks often blur it.

A relative pin freezes a piece in front of something valuable but not the king. Black's 3...Bg4 and White's 9. Bg5 are both relative pins: the pinned knight could legally move, at the cost of the queen behind it. A relative pin is a threat about price.

An absolute pin freezes a piece in front of the king. After 11...Nbd7 the knight on d7 cannot legally move at all, and after 13...Rxd7 neither can the rook that replaces it. An absolute pin is a rule, not a price.

Morphy's attack runs on the conversion of one into the other. The relative pin on f6 holds the knight in place while the absolute pin on d7 is built and then fed, piece after piece, into the same square. The most useful sentence in the whole game might be this one: a pin is worth what you can keep pointing at it. Black's early pin had nothing behind it. White's pins had everything behind them.

Document 6. A note on consultation chess

The game was not one against one. Two players sharing a side, whispering over each move, is called consultation chess, and it was common in the nineteenth century as a social game. It is tempting to think two heads would defend better than one. The evidence of this game is that two heads agreed on a plan, the early pin, and then defended it together. Consultation tends to reinforce a shared first idea rather than replace it. You can test that yourself: play a game in consultation with a friend, write down the first plan you agree on, and see how long you keep it after it has stopped working.

Document 7. Your position

Set up the position after 14... Qe6, White to move. Before you look at the score, write down your candidate moves and, for each, what Black does next. Then decide. When you have decided, play it out against the engine in RookDojo, and compare your line to Morphy's. If yours wins too, find out whether it wins faster or slower, and why.

Document 8. Questions for the seminar

Decide your answer before the group does, and write it down.

1. Was 3...Bg4 a mistake, or a reasonable idea played one move too early? What would Black need to have in play for the pin to be worth keeping?
2. Morphy refused a free pawn on move nine. Name a situation outside chess in which taking the sure small gain would have cost you the larger chance. Was refusing it a risk, or the safer choice?
3. The score has survived unchanged; the opera has not. What does that tell you about which details people bother to record, and why?
4. If you had to teach one idea from this game to someone who has never played chess, which would you pick, and how would you explain it without a board?

There is no single right answer to any of these. A good answer names its reason and says what would change your mind.

Document 9. The Honest Page

• Known: the seventeen moves; the players; that it was played at the Italian Opera in Paris in the autumn of 1858.
• Disputed: which opera was playing, and on which night (Norma or, most probably, The Barber of Seville, 4 November 1858; Edward Winter, Chess Notes).
• Legend: that Morphy sat facing the stage and played with half his attention on the singing. It is told often; it is not recorded.