Four Knights Game

1. e4White plays e4.
2. e5Black replies e5, the classical open game.
3. Nf3Nf3 develops and attacks e5.
4. Nc6Nc6 defends the pawn and develops.
5. Nc3Nc3 brings out the fourth knight. Complete symmetry — this is the Four Knights.
6. Nf6Black mirrors with Nf6, attacking e4.
7. Bb5Bb5 — the Spanish Variation. The bishop pins the c6 knight, borrowing the main idea from the Ruy Lopez.
8. Bb4Bb4 mirrors again. Black is content to copy for now, and there is nothing wrong with it.
9. O-OWhite castles, getting the king safe and connecting the rooks.
10. O-OBlack castles too. The position remains perfectly symmetrical.
11. d3d3 supports e4 and opens the c1 bishop's diagonal — a solid, flexible move.
12. d6d6 does the same for Black. Stockfish reads about +0.35 for White: the small edge that comes from moving first, nothing more.

The Rubinstein Counter-Gambit. Black answers the pin with 4...Nd4!, sidestepping into the centre instead of defending. If White grabs the pawn on e5, Black gets tremendous activity for it. Stockfish reads about -0.15 after 6...O-O, which for a gambit line is an excellent result for Black — this one is genuinely sound.

1. e4White plays e4.
2. e5Black plays e5.
3. Nf3Nf3 attacks e5.
4. Nc6Nc6 defends.
5. Nc3Nc3 — the Four Knights.
6. Nf6Nf6 completes the symmetry.
7. Bb5Bb5 pins the c6 knight.
8. Nd4Nd4! The Rubinstein. Rather than break the pin, Black jumps the knight into the centre and offers the e5 pawn.
9. Ba4Ba4 keeps the bishop on the board and maintains some pressure.
10. Bc5Bc5 develops and points at f2, the square Black's whole setup targets.
11. Nxe5Nxe5 accepts the offer — grabbing the pawn but falling behind in coordination.
12. O-OBlack castles. Fully developed with active pieces for the pawn, and the engine agrees: about -0.15, meaning Black is doing fine.

The Scotch Four Knights. White breaks the symmetry with 4.d4 and heads for open, Scotch-like play with all four knights already out. It is the most testing way to play the position, and trading on c6 leaves Black with doubled pawns to worry about all game. Stockfish reads about +0.3 for White.

1. e4White plays e4.
2. e5Black plays e5.
3. Nf3Nf3 attacks e5.
4. Nc6Nc6 defends it.
5. Nc3Nc3 develops the fourth knight.
6. Nf6Nf6 mirrors.
7. d4d4! Instead of the quiet Bb5, White opens the centre immediately.
8. exd4Black takes on d4 — the standard reply.
9. Nxd4White recaptures with the knight, centralising it.
10. Bb4Bb4 pins the c3 knight, borrowing an idea from the Nimzo-Indian.
11. Nxc6Nxc6! Trading before the pin can bite, and damaging Black's structure.
12. bxc6bxc6 accepts the doubled pawns but opens the b-file for the rook. Engine: about +0.3 for White.

The Halloween Gambit — White sacrifices a whole knight on move four for a giant pawn centre and the chance to chase Black's pieces backwards. It should not work, and Stockfish agrees at about -1.3 for White. But the positions are so strange that many opponents go wrong quickly, which is exactly why it remains popular in blitz.

1. e4White plays e4.
2. e5Black plays e5.
3. Nf3Nf3 attacks e5.
4. Nc6Nc6 defends.
5. Nc3Nc3 — the Four Knights, still all normal.
6. Nf6Nf6 completes the symmetry.
7. Nxe5Nxe5?! The Halloween Gambit. White gives up a whole knight for two pawns and a big centre.
8. Nxe5Black takes the knight — declining would simply leave White a pawn up for nothing.
9. d4d4! The idea. White chases the knight and starts rolling the centre forward.
10. Ng6Ng6 retreats to the best available square.
11. e5e5 drives the second knight backwards and takes even more space.
12. Ng8Ng8 — the knight is forced all the way home. White has a dream centre but is a piece down; Stockfish reads about -1.3, so with accurate defence Black should win.