Slav Defense

1. d4White opens with d4, the classical queen's pawn move.
2. d5Black replies d5, mirroring in the centre.
3. c4c4 — the Queen's Gambit. White offers the c-pawn to deflect Black's centre.
4. c6c6! The Slav. Black defends d5 with the c-pawn rather than ...e6, keeping the c8 bishop's diagonal open.
5. Nf3White develops Nf3, controlling e5 and preparing to castle.
6. Nf6Black develops Nf6, fighting for e4 and continuing natural development.
7. Nc3Nc3 adds a third attacker to d5 and prepares e4.
8. dxc4Now Black takes on c4. This only works because ...b5 is available to hang on to the pawn.
9. a4a4! Preventing ...b5 before it can happen. It costs a tempo and slightly weakens b4, but Black cannot keep the pawn.
10. Bf5Bf5! The whole justification of the Slav. The bishop develops actively outside the pawn chain — in the Queen's Gambit Declined it would be stuck behind e6 for the entire game.
11. e3White plays e3, solidifying d4 and preparing to recapture on c4 with the bishop.
12. e6Black completes the structure with e6. Solid and harmonious; Stockfish reads about +0.35 for White, a normal opening edge against a very sound defence.

The Meran Variation of the Semi-Slav — one of the most heavily analysed systems in all of chess. Black plays both ...c6 and ...e6, giving up the free bishop for a structure that is very hard to crack, then takes on c4 and expands with ...b5. Play gets sharp fast. Stockfish reads the position at about +0.4 for White.

1. d4White plays d4.
2. d5Black plays d5.
3. c4c4 — the Queen's Gambit.
4. c6c6, heading for Slav structures.
5. Nc3Nc3 develops and pressures d5.
6. Nf6Black develops Nf6.
7. e3e3 — a modest move that solidifies d4 and frees the f1 bishop.
8. e6e6! This is the Semi-Slav. Black accepts that the c8 bishop is shut in, in exchange for a structure that is almost impossible to break down.
9. Nf3Nf3 completes the natural development.
10. Nbd7Nbd7 supports c5 and e5, the two freeing breaks.
11. Bd3Bd3 develops actively, pointing at h7.
12. dxc4dxc4! The Meran. Black takes and prepares ...b5 with tempo, grabbing queenside space. Engine reading: about +0.4 for White in a very double-edged position.

The Botvinnik Variation, widely considered the sharpest opening line in serious chess. White plays 5.Bg5 and then throws the centre forward with 6.e4; Black grabs everything and hangs on. Both sides need to know twenty moves of theory. Stockfish reads about +0.45 for White, but the practical result depends almost entirely on preparation.

1. d4White plays d4.
2. d5Black plays d5.
3. c4c4, the Queen's Gambit.
4. c6c6, the Slav move order.
5. Nf3Nf3 develops.
6. Nf6Black develops Nf6.
7. Nc3Nc3 builds pressure on d5.
8. e6e6 turns this into a Semi-Slav.
9. Bg5Bg5! Pinning the knight on f6 and inviting the sharpest line in the opening books.
10. dxc4Black grabs the pawn on c4.
11. e4e4! White builds a huge centre and offers still more material for the initiative.
12. b5b5 holds on to the extra pawn and the fight begins in earnest. Around +0.45 for White, but this is preparation territory, not intuition.

The quiet line with 4.e3, and a good illustration of Slav logic. Black gets the bishop out to f5 first and only then plays ...e6, so the bishop is never trapped behind the pawn chain. White's standard plan is Nh4 to trade it off. Stockfish reads about +0.3 — a small pull, and an easy position for Black to play.

1. d4White plays d4.
2. d5Black plays d5.
3. c4c4 offers the gambit.
4. c6c6 — the Slav.
5. Nf3White develops Nf3.
6. Nf6Black develops Nf6.
7. e3e3 is quiet and solid, but it commits the c1 bishop to staying home for a while.
8. Bf5Bf5! Correct order — the bishop gets out before ...e6 could ever shut it in.
9. Nc3Nc3 develops and eyes d5.
10. e6Now ...e6 is safe: the bishop is already outside the pawn chain.
11. Nh4Nh4 attacks the bishop, the standard way to fight it.
12. Bg6Bg6 keeps the bishop on the board and the diagonal. The position is comfortable for Black — Stockfish reads about +0.3.