Nimzo-Indian Defense

1. d4White plays d4, taking central space.
2. Nf6Black develops Nf6, controlling e4 in hypermodern style.
3. c4c4 stakes out more space and prepares Nc3.
4. e6e6 opens the diagonal for the dark-squared bishop and prepares ...d5.
5. Nc3Nc3 develops and, crucially, supports the e4 push.
6. Bb4Bb4! The Nimzo-Indian. The bishop pins the knight on c3 — and with it, White's control of e4.
7. e3e3 — the Rubinstein System, the most flexible and popular answer. White develops quietly and keeps all options open.
8. O-OBlack castles, getting the king safe before the centre resolves.
9. Bd3Bd3 develops toward the kingside and eyes h7.
10. d5d5! Black finally stakes a claim in the centre, fighting for e4 with pawns as well as pieces.
11. Nf3Nf3 completes the minor-piece development.
12. c5c5! The thematic strike at the base of White's centre. Stockfish reads about +0.15 — practically equal, which is exactly the Nimzo's reputation.

The Classical Variation with 4.Qc2 — the most popular try at grandmaster level. The queen defends c3 ahead of time, so if Black trades on c3 White recaptures with the queen and keeps a perfect pawn structure plus the bishop pair. Black's compensation is time and a solid setup. Stockfish reads about +0.25 for White.

1. d4White plays d4.
2. Nf6Black develops Nf6.
3. c4c4 gains space.
4. e6e6 prepares the bishop's development.
5. Nc3Nc3 supports e4.
6. Bb4Bb4 pins the knight — the Nimzo.
7. Qc2Qc2! The Classical. The queen defends c3 in advance, so the doubled pawns will never appear.
8. O-OBlack castles and gets the king to safety.
9. a3a3 puts the question to the bishop immediately.
10. Bxc3Black trades on c3, which is the point of the whole opening.
11. Qxc3Qxc3! Recapturing with the queen. White has the bishop pair and a clean structure — exactly what 4.Qc2 was for.
12. b6b6 prepares ...Bb7, targeting e4 along the long diagonal. Engine: about +0.25 for White.

The Sämisch Variation. White plays 4.f3 with one blunt idea: push e4 no matter the cost. Black trades on c3 and White ends up with tripled-looking queenside pawns and a monster centre. Extremely committal for both sides. Stockfish actually gives Black a hair here, about -0.2, but practical results have always been much better than the engine number suggests.

1. d4White plays d4.
2. Nf6Black plays Nf6.
3. c4c4 takes space.
4. e6e6.
5. Nc3Nc3 develops.
6. Bb4Bb4 — the pin.
7. f3f3!? The Sämisch. Crude but effective: White simply prepares e4 by brute force.
8. d5d5 challenges the centre before White can execute the plan.
9. a3a3 forces the bishop to decide.
10. Bxc3Black takes on c3.
11. bxc3bxc3! The pawns are damaged but the centre is enormous and the c1 bishop is free.
12. c5c5 hits d4 immediately. Sharp and unbalanced — engine says about -0.2, though White's practical scores here are excellent.

The Leningrad Variation with 4.Bg5 — pin against pin. White develops the bishop actively and puts pressure on f6 rather than worrying about c3. The play becomes concrete very quickly, with White grabbing space via d5 and Black counterattacking. Stockfish reads about -0.15, essentially level.

1. d4White plays d4.
2. Nf6Black plays Nf6.
3. c4c4.
4. e6e6.
5. Nc3Nc3 develops and supports e4.
6. Bb4Bb4 pins the knight.
7. Bg5Bg5! White answers one pin with another, hitting the f6 knight.
8. h6h6 puts the question to the bishop right away.
9. Bh4Bh4 keeps the pin rather than trading on f6.
10. c5c5 strikes at the centre — Black's standard freeing break.
11. d5d5! White closes the centre and takes space, gaining time on the e6 pawn.
12. d6d6 supports the structure and prepares to complete development. The engine reads about -0.15 — completely balanced.