Opening Courses (882)

A single capture gives this repertoire its shape. In GM Sina Movahed's Ruy Lopez it's Bxc6 — White trading the Spanish bishop for the c6-knight, an old resource that here turns on when it's played. Movahed's case is structural: reach for it at the right moment and Black is left with pieces poorly suited to the position that results.

His foundation is the deferred exchange: 5...Be7 6.Bxc6. Instead of capturing on move four, Movahed waits until Black has committed the bishop to e7 and the knight to f6 — and then argues those very pieces sit awkwardly for the pawn structure that arises after ...dxc6. The aim is not to refute the Ruy Lopez, but to hand Black an unfamiliar middlegame from an entirely familiar move order.

For the better part of a century, the Rubinstein Variation (4.e3) has been White's most trusted answer to the Nimzo-Indian, and for one reason above all: it commits to nothing. The knight stays home on g1, waiting to choose between f3 and e2 until Black has shown his hand.
GM Alexey Dreev's answer is to out-wait the waiting move. At the heart of this repertoire sits a single, unassuming rook move — 5...Re8 — that hands the burden of commitment straight back to White. If the knight steps to f3, Black replies ...d6 and prepares the ...e5 break; if it goes to e2, Black switches to ...d5, where the e2-knight is awkwardly placed. Whichever square White picks turns out to be the wrong one. That is the "reload": an old main line given a new life, driven by move-order rather than memorization.

The French Defence has always carried one complaint louder than the rest: the light-squared bishop on c8, sealed behind its own pawns before the game has properly begun. The Fort Knox answers that complaint before it can be made. After 1.e4 e6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Bd7, Black's problematic piece steps out through d7 to c6 while the diagonal is open — the piece that usually spends the game being restricted becomes the first one developed.
The idea is simple and durable. The bishop on c6 is no longer a liability but a piece which will be traded — Black is content to give it up for a white knight, often with ...Bxe4, easing the cramped position. Black finishes developing with ...Nd7, ...Ngf6, ...Be7 and short castling, reaching a compact structure with no real weaknesses to attack, and only then looks to challenge White's centre with ...c5 or, in some lines, ...e5.

For most of the Carlsbad's history, the conversation began from a single assumption: Black answers 3.Nc3 with 3...Nf6, and the familiar Exchange structure follows. That assumption no longer holds. In around half of today's games, Black sidesteps the automatic knight move and reaches instead for a different order — the Triangle, an early ...a6, a Ragozin-style ...Bb4, the fashionable ...h6, or a direct ...c5. Carlsbad Structure for White – Part 4 by GM Pier Luigi Basso is built around exactly this shift, completing the repertoire against everything Black plays instead of 3...Nf6.

For decades, meeting the Caro-Kann with 3.e5 was treated as the modest reply. Releasing the central tension so early seemed to hand Black the very thing the opening is chosen for — a light-squared bishop developed to f5 in the open air, before ...e6 ever shuts it in. Nigel Short's advocacy in the early 1990s reshaped that judgment, showing that White's extra space in the Advance Variation is a lasting asset rather than a concession.
Crushing the Caro-Kann with 3.e5: White's Space Advantage, the new course by IM Deboushnik De, extends that idea instead of repeating it. Where Short built the space advantage slowly, this repertoire expands on both wings and starts posing questions from move four, aiming to deny Black the settled, comfortable game the Caro-Kann promises.

Somewhere along the way, the Italian Game quietly changed character. The first three moves stayed the same — 1.e4 e5 2.Nf3 Nc6 3.Bc4 — but the fourth became a slow d2-d3, and the Italian became known for patient maneuvering rather than early fireworks.
GM Mitrabha Guha's new course restores the Italian's older, faster character. The starting position is the familiar one, but at every crossroad, the repertoire takes the direct road rather than the quiet one.

Ask a well-prepared opponent how they meet the Advance today, and you'll hear a dozen fashionable answers: an early ...Qc7, ...Bd7–b5 maneuvers, ...Nge7 setups designed to sidestep theory. GM Andrea Stella takes a different road. In French Defense for Black – Part 3, he goes back to what he calls the "good and old mainline" — 5...Qb6, 6...c4, 7...Na5 — the classical treatment of White's most ambitious try against the French.
The choice is deliberate. Stella recommends 5...Qb6 not because it hides from theory, but to keep the "classical spirit": pressure on d4 and b2 from move five, a healthy structure, and a plan Black actually wants to play. The result is presented as a sound, fighting repertoire against 3.e5 rather than a survival guide.

Classical theory treated an early rook-pawn move as a small concession — a tempo spent on nothing while the real pieces waited. The engine age has quietly overturned that verdict. Again and again, a flexible waiting move has proven worth more than a routine developing one, and today's practice is full of early …h6 and …a6 ideas an older generation would have dismissed as slow.
4…h6 in the Queen's Gambit Declined is a clean expression of that shift. After 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 h6, Black spends a move to deny White the g5-square — and with it, the whole theoretical forest that grows around the Bg5 pin.

For most of its long life, the Philidor has been filed under "solid but passive" — an opening you reach for to hold the balance, not to fight for the initiative. In this new edition, GM Baadur Jobava and GM Pier Luigi Basso argue that the reputation is out of date.
The whole repertoire turns on a single reassessment. Where Black used to keep the central tension with ...c6 and settle into a slightly cramped position, the authors now release it at once with ...exd4, plant a knight on e5, and obtain fast, comfortable piece play.
That one idea runs through the entire course, and it is why this is a genuinely new course rather than a revision of the previous edition. The authors are explicit about it: the main directions have been rebuilt, and many chapters rewritten from scratch.

There is no shortage of repertoires against the London System. What there has never been is seven of them, side by side, produced independently by strong players who did not know what the others were writing.
That is what the Modern Chess Autumn Challenge produces, and this database is the result of its first stage. Each of the seven participants was handed the same two problems — a repertoire for Black against the Classical London (1.d4 d5 2.Nf3 Nf6 3.Bf4) and against the Jobava London (1.d4 d5 2.Nc3 Nf6 3.Bf4) — and each solved them their own way.
Fourteen recommendations. No two alike.