[Event "Czech Variation - Classical Slav (4...dxc4 5.a4 Bf5)"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 {Occupy the center symmetrically.} 2. c4 {Queen's Gambit by White.} c6 {Slav Defense (ECO D10-D19). We support d5 with c6 instead of e6. CRUCIAL ADVANTAGE: the c8 Bishop is NOT locked in, it can develop to f5. Major opening played by Kramnik, Carlsen, Anand.} 3. Nf3 Nf6 4. Nc3 dxc4 {Czech Variation (ECO D17-D19): THE MAIN LINE of the Slav. TAKE! The plan is brilliant: develop the Bishop to f5 BEFORE e6. THEORY: consensus, this is the most played and most theoretical variation of the Slav.} 5. a4 {THEORY: near-mandatory move for White. Prevents ...b5 which would hold the c4 pawn.} Bf5 {THE KEY MOVE of the entire repertoire. The Bishop comes OUT before e6 locks it in. This Bishop will be active the entire game. Compare with the QGD (2...e6) where the c8 Bishop is the "bad Bishop" for 30 moves. THEORY: total consensus, this is the move that defines the Slav.} 6. e3 e6 {Now e6 is OK because the Bishop is already out!} 7. Bxc4 {White recovers the pawn.} Bb4 {Czech Variation, Classical System. Pin the c3 Knight! THEORY: main line. Plan: O-O, ...Nbd7, then ...c5 at the right moment. TYPICAL MISTAKE: playing ...c5 too early without having finished development.} *

[Event "Slav Exchange (3.cxd5 cxd5)"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. c4 c6 3. cxd5 {Slav Exchange (ECO D10). White simplifies early. THEORY: often chosen to make a draw, but Black can play for a win.} cxd5 {Symmetrical position.} 4. Nc3 Nf6 5. Nf3 Nc6 {Develop actively. The c6 Knight targets d4 and e5.} 6. Bf4 Bf5 {ALWAYS: Bishop out BEFORE e6! This principle applies in ALL Slav variations. Plan: ...e6, ...Bd6 (offer the trade of dark-squared Bishops), ...O-O. Strategy to know: the minority attack (...a5, ...b5, ...b4) to create weaknesses in White's queenside pawns.} *

[Event "vs London System (2.Bf4) - VERY COMMON"]
[White "Adversaire"]
[Black "Anti-London"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. Bf4 {London System (ECO D00). You will see this VERY often at all levels! Favorite opening of club players because White plays the same moves no matter what Black does. But we have a VERY good plan against it.} Nf6 3. e3 c5 {THE KEY anti-London: counter-attack the center IMMEDIATELY with ...c5! THEORY: main response recommended by Johnsen & Kovacevic in their reference book on the London. Do NOT play passively ...e6-...Bd6 which gives White exactly what they want (comfortable c3-d4-e3 pawn triangle).} 4. c3 {White reinforces d4.} Nc6 {Pressure on d4.} 5. Nd2 e6 {Prepare ...Bd6.} 6. Ngf3 Bd6 {The poison move! We OFFER the trade of dark-squared Bishops. THEORY: standard and consensus idea. If 7.Bxd6 Qxd6 - our Queen is well centralized. If 7.Bg3 Bxg3 8.hxg3 - White's g2-g3 pawns are doubled and weak long-term. In both cases Black is happy! PLAN: O-O, then ...b6 + ...Bb7 or ...Qe7 followed by ...e5.} *

[Event "vs 2.Nf3 - Transpositions"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. Nf3 {White waits before choosing their system. THEORY: very common, allows White to avoid certain variations.} Nf6 3. c4 (3. Bf4 {Late London - same response!} c5 {THEORY: always counter-attack with ...c5 against the London, regardless of the move order.} 4. e3 Nc6 {Same anti-London plan: ...e6, ...Bd6, offer the trade of Bishops.}) (3. e3 {Colle System (ECO D05). Passive - White locks in the c1 Bishop.} Bf5 {Develop the Bishop WHILE you can! SLAV REFLEX.} 4. Bd3 e6 5. O-O Bd6 {Harmonious development. Plan: ...O-O, ...Nbd7, ...c5.}) c6 {Transposes into the Slav! Our repertoire applies normally. That's the advantage of a coherent repertoire: transpositions work in our favor.} *

[Event "vs passive moves - 2.e3, 2.c3, 2.g3"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. e3 {Passive. THEORY: White voluntarily locks in the c1 Bishop! Positional mistake.} Nf6 3. Nf3 Bf5 {SLAV REFLEX: as soon as White doesn't threaten the center, DEVELOP THE BISHOP! This theme recurs in every variation of our repertoire.} 4. Bd3 e6 5. O-O Bd6 {Harmonious development. Plan: ...O-O, ...Nbd7, ...c5. Position at least equal because White played too passively.} *

[Event "vs 2.c3 - slow preparation"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. c3 {Prepares e4? But it's slow.} Nf6 3. Nf3 Bf5 {SLAV REFLEX: Bishop out! White hasn't threatened the center so we develop freely. Plan: ...e6, ...Bd6, ...O-O, ...Nbd7, ...c5.} *

[Event "vs 2.g3 - Catalan Fianchetto"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. d4 d5 2. g3 {Catalan Fianchetto. THEORY: respectable but slow system.} Nf6 3. Bg2 Bf5 {Again and always: SLAV REFLEX — Bishop out! The Bg2 is strong but our rapid development compensates. Plan: ...e6, ...Bd6, ...O-O, ...Nbd7, ...c5.} *

[Event "vs English Opening (1.c4) - SLAV TRANSPOSITION"]
[White "Adversaire"]
[Black "Slav Defense"]
[Result "*"]
[Orientation "black"]

1. c4 {English Opening (ECO A10-A39). Rare below 1500 Elo but important to know. White controls d5 without committing to d4 yet. Don't panic — we have a simple plan that uses our Slav knowledge.} c6 {THE KEY MOVE for Slav players! We prepare ...d5 exactly like in the Slav. If White plays d4, we transpose directly into our repertoire. THEORY: solid and practical, recommended by multiple repertoire authors for d5/Slav players.} 2. d4 (2. Nf3 {White avoids d4.} d5 {Take the center! We now have a strong d5 pawn supported by c6.} 3. cxd5 cxd5 {Symmetrical but we're fine. This is like an Exchange Slav where White hasn't played d4. Plan: ...Nf6, ...Bf5 (SLAV REFLEX — Bishop out before e6!), ...e6, ...Bd6, ...O-O.} 4. d4 {White plays d4 later — transposition to Exchange Slav.} Nf6 5. Nc3 Bf5 {SLAV REFLEX again. Bishop out BEFORE e6. Same principle as every Slav variation.}) (2. e4 {Aggressive — White grabs the center.} d5 {Challenge immediately!} 3. cxd5 cxd5 4. exd5 Nf6 {We sacrifice a pawn temporarily for rapid development. Similar idea to the Scandinavian — develop the Knight toward d5.} 5. Nc3 Nxd5 {Pawn recovered. Plan: ...e6, ...Bd6, ...O-O. THEORY: equal position, Black has no problems.}) (2. g3 {Fianchetto English.} d5 {Take the center!} 3. cxd5 cxd5 {Same idea. Solid central pawn on d5.} 4. Bg2 Nf6 5. Nf3 Bf5 {SLAV REFLEX. Our Bishop is active while White's fianchetto doesn't challenge our center directly. Plan: ...e6, ...Bd6, ...O-O, ...Nbd7.}) {Most common — White plays d4 anyway.} d5 {We're now in a Slav! 1.d4 d5 2.c4 c6 with colors swapped in move order. Our entire Slav repertoire applies. THEORY: direct transposition.} *
