Bogo-Indian Defence

1.d4 Nf6 2.c4 e6 3.Nf3 Bb4+

Check on move three, trade the bishop, castle, and play ...d6 and ...e5: a solid Black opening with almost nothing to memorise. White gets a little space and you get a position where every natural move is fine and the traps all point their way.

Spar this opening

Your setup

Bishopb4
Knightf6
Knightc6 / d7
Queene7
Rooke8
Pawnse6 d6
CastleO-O

Bxd2+ or Bxc3 before e5. Trade the bishop before you play ...e5. While the bishop still sits on b4, the queen on e7 is its only guard, so after ...e5 dxe5 you cannot recapture with the queen without dropping the bishop to Bxb4.

d6 before e5. ...d6 first, then ...e5. Without a pawn on d6 the e5-pawn is defended by at most a knight, and dxe5 simply wins it or drags your pieces to awkward squares.

Ideas

The check is a question, not an attack

...Bb4+ asks White to block with a piece. Whatever blocks is a little worse off.

Bd2 puts a bishop on a square where it only waits to be traded. Nbd2 puts a knight where it blocks the c1-bishop. Nc3 turns the game into a Nimzo-Indian. None of it wins anything, but every answer costs White a small piece of comfort, and you develop with tempo.

After Bd2, guard the bishop first

Bd2 attacks b4. ...Qe7 defends it and prepares ...e5. Never castle here.

The bishop on b4 has no defender once Bd2 lands, and a careless ...O-O or ...d5 loses it to Bxb4 on the spot. ...Qe7 solves it: the queen guards b4, eyes e5, and will recapture on d2 later if needed.

Trade on d2 when a3 asks

a3 puts the question. Take on d2; retreating costs a move and keeps a target on the board.

The bishop has done its job by making White block. When a3 comes, ...Bxd2+ trades it for whatever blocked and leaves you with a tidy position. Retreating to e7 or a5 loses time and the bishop can be hit again.

The ...e5 break

With ...d6 in and the bishop traded, ...e5 frees your whole position.

The pawn on e5 gives your knights squares, opens the e-file for the rook and stops White's centre from expanding. If d5 comes, the knight steps back to b8 and returns via d7 or a6; if dxe5 dxe5, the position is level and simple.

Against Nc3: you are in a Nimzo-Indian

The knight on c3 can be taken. ...Bxc3 and then ...Ne4 hits whatever recaptured.

When White blocks or follows up with Nc3, the bishop has a knight to bite on. Trading on c3 and jumping ...Ne4 gains time against the piece on c3, and if a pawn ever recaptures, White has doubled pawns to look after. Castle and play ...d6 and ...e5 as usual afterwards.

Do not rush ...e5

...e5 with the bishop still on b4 loses a pawn: dxe5 and ...Qxe5 drops the bishop.

The queen on e7 is doing two jobs, guarding b4 and eyeing e5. It cannot do both after dxe5. Trade the bishop first, put a pawn on d6, and then ...e5 is properly supported.

When the book runs out

Castle, ...d6, ...e5, rook to e8. Then knights to e4 or c5 and let White come to you.

The Bogo gives you a sound position rather than a target. After ...e5 you keep the tension: a rook on e8, a knight ready for e4 or c5, ...a5 to stop b4, and ...h6 to stop Bg5. Trade when it is equal and let White overreach.

The structure

The Bogo picture: the check has been answered, the bishop is about to be traded on d2, the queen on e7 stands behind the coming ...e5 break.

Traps

The undefended bishop

d4 Nf6 c4 e6 Nf3 Bb4+ Bd2 O-O Bxb4

The tell: White blocks the check with Bd2 and you reach for the most natural move on the board.

The bishop on b4 has no defender the moment Bd2 lands. Castling, ...d5 and ...b6 all drop it to Bxb4. Every move after 4.Bd2 has to deal with the bishop: ...Qe7 guards it, ...a5 guards it, ...Bxd2+ trades it.

Blocking with the queen

d4 Nf6 c4 e6 Nf3 Bb4+ Qd2 Bxd2+ Bxd2

The tell: White answers the check with Qd2 instead of a bishop or knight.

The queen steps onto the square your bishop attacks. ...Bxd2+ wins a queen for a bishop and White recaptures with a bishop or knight. Beginners do this because Qd2 looks like it defends everything; it defends nothing.

...e5 with the bishop still on b4

d4 Nf6 c4 e6 Nf3 Bb4+ Bd2 Qe7 g3 e5 dxe5 Qxe5 Bxb4

The tell: You know ...e5 is the plan and the queen on e7 looks ready to support it.

The queen on e7 has two jobs: guarding the bishop on b4 and backing up e5. After dxe5 she can only do one. ...Qxe5 recaptures the pawn and Bxb4 takes the bishop. Trade on d2 first, put a pawn on d6, and then ...e5 is safe.

Model games

Main line: 4.Bd2 Qe7

d4 Nf6 c4 e6 Nf3 Bb4+ Bd2 Qe7 g3 Nc6 Bg2 Bxd2+ Nbxd2 d6 O-O O-O e4 e5 d5 Nb8 Ne1 a5

The check, the guard, the trade, then ...d6, castle and ...e5. When White closes with d5 the knight steps back to b8 and returns via d7; ...a5 stops b4.

Nimzowitsch line: 4.Nbd2

d4 Nf6 c4 e6 Nf3 Bb4+ Nbd2 O-O a3 Bxd2+ Bxd2 d6 e3 Nbd7 Bd3 e5 O-O Re8 Qc2 Qe7

White blocks with the knight to keep the bishop pair. You castle, trade when a3 asks, and prepare ...e5 with ...d6 and ...Nbd7 so the break is fully supported.

Against Nc3: take and hit c3

d4 Nf6 c4 e6 Nf3 Bb4+ Bd2 Qe7 Nc3 Bxc3 Bxc3 Ne4 Rc1 O-O g3 d6 Bg2 Nxc3 Rxc3 e5

White adds Nc3 and the bishop takes it. ...Ne4 hits the recapturing bishop, White spends a rook move defending, and after the trade on c3 you get ...e5 with a level, easy position.

How the coach grades a move

Every move you play gets one of six grades, from the engine’s view of the position, with the book’s verdict taking over when it is harsher. The sentence beside it is always the reason. Tap it for what the move did, why this opening wants it, and whether anything was better.

Best: Nothing better was available.
Good: Within a few percent of best. Noise at this depth.
Playable: A small real gap. The better move is named, play goes on.
Inaccuracy: Seven to twelve points of winning chances. The game stops to show you.
Mistake: Twelve or more, or a move the book warns against, or a broken order rule.
Blunder: Twenty-five or more. Usually material.

Catalogued as E11 in the Encyclopaedia of Chess Openings, the reference index most databases sort by.