An opening course for White (ECO D02)
The London is 1.d4 and 2.Bf4: the queen's bishop leaves the pawn chain before e3 shuts it in, and White builds the same house almost regardless of what Black does. Pawns on d4, e3 and c3, knights to f3 and d2, bishop to d3, h3 for the retreat square, castle, then a knight to e5. That is the whole skeleton, and learning it once buys you a playable middlegame against most of Black's first moves. The cost is real and worth saying out loud: you reach a handful of the same pawn structures over and over, so you learn them deeply and learn the rest of chess more slowly. This course teaches the plans behind the setup rather than a move list, and it spends most of its length on the two places where Black genuinely tests you, an early ...c5 with ...Qb6 and a King's Indian fianchetto.
This course is part of your daily work.
In most 1.d4 openings the c1-bishop spends ten moves trapped behind its own e3 pawn. Playing Bf4 on move two solves that problem before it exists. Everything else in the system is arranged to keep that bishop on a good diagonal, and that is why h3 and the retreat squares h2 and g3 matter more than they look.
A knight on e5, held by the d4 pawn and the f4 bishop, is the standard source of every attack in this opening. If Black spends moves preventing it or trading it off, he is spending moves on your plan rather than his.
Against a Black king with a pawn on h7, the bishop belongs on d3, usually with the queen behind it on f3 or c2. Against a fianchetto there is no h7 to aim at, so the bishop takes a modest square and White plays for queenside space with c4 and a4 instead. Picking the wrong one of these two is the most common way the London goes flat.
The c-pawn is the one real decision in the system. Play c3 when Black already has pieces aimed at d4: the pawn props the centre up and the structure holds. Play c4 when Black's light-squared bishop has left c8, because then the pawn hits d5 and frees b3 for the queen, and b7 has nobody looking after it.
Learning order, one scoresheet per chapter. The coach serves review one line a day; enter any line directly when you want it now.
One line, no theory. Play through it once and you have the skeleton that every other chapter hangs on.
Black plays ...d5, ...Nf6, ...e6 and gets on with it. These are the positions you will reach most often, and the three lines here cover the three things Black can do about your bishop: leave it alone, trade it, or ignore the kingside and get queenside play.
This is where the London gets tested. Black plays ...c5 hitting d4 and ...Qb6 hitting both d4 and b2, before White has castled or covered anything. Johnsen and Kovacevic treat it as the critical line of the whole system. There are two honest answers. Nc3 offers the b2 pawn and is much the more testing; Qc1 declines everything and keeps a small, safe game. The first three lines cover Nc3, and the last one is there if you want the quiet life.
Black plays ...g6 and ...Bg7 and sets up a King's Indian. The one rule that matters here is that Bd3 is pointless: there is no h7 hook when the king sits behind a fianchetto, so the bishop goes to e2 and White plays for space on the other wing with c4 and a4. Getting this wrong is the most common way London players end up in a dull position they cannot win.
Black plays ...Bf5 to get the bad bishop outside the pawn chain before ...e6 locks it in. It is a good idea with one hole in it: the bishop on c8 was the only piece defending b7. Every line here is White collecting on that. Note the move order, because it is the thing this course had to correct: Qb3 is illegal while the c2 pawn is at home, so White plays c4 or c3 first, and only then goes to b3.
Club games that started in the London System produced these tactics, and you solve every one from White's side, the seat you actually sit in. Difficulty follows your solving, the same as the puzzle room.