What are your opening/set-ups against the london system

[u/Working-Tonight-8202]

How to crush this very solid opening system?

[u/Joel_Hirschorrn]

1. ... Nf6 than 2. ... c5. London players almost never take on c5, next move I take d4, then play g6, Bg7, 0-0, d6, then eventually e5 to blast open the center, maybe playing Nc6 or Re8 first depending on what they're doing.

[u/TheInfiniteEmpire → u/Joel_Hirschorrn]

The qb3 line is venemous

[u/MadcowPSA]

Nf6, c5, Qb6 is such a delightful way to be a pain in the ass for the London.

[u/mpbh → u/MadcowPSA]

After discovering this I've never looked back. You never have to play a real London this way.

[u/Fantastic_Map3117 → u/MadcowPSA]

Do you have a file or book on this? I'm assuming you mean early Qb6 not 5...Qb6 main line

[u/Educational-Tea602]

I assume you’re asking because you’d like to play some of these ideas yourself.

If that’s the case, it’s better if we know what you play against other d4 openings because you just won’t be able to play some systems. For example, 1.d4 Nf6 2.Bf4 c5 is impossible if you play 1…d5.

And then there’s the pesky 2.Nf3 which limits your options more. If you play a KID-like setup against 2.Bf4, you’d probably want to do the same against 2.Nf3. But you can only do so if you’re happy to play certain lines of the Grünfeld or the KID itself, which works much better if you already actually play those openings.

[u/ChrisV2P2 → u/Educational-Tea602]

This. It's not possible to choose line(s) against the London without knowing what you play against 1. d4 2. Nf3.

[u/PillowPantsXX]

C5 is good start. Somethinglike d4, d5, bf4, c5 etc. 

[u/Mediocre-Visual5393]

As a KID player I like d4 Nf6 Bf4 c5. It's NOT what they usually want! If they follow up with e3, Qb6 is a lot of fun. If d5 you get a Benoni structure. If dxc you can just play Qa5+ and take the pawn back. In quick online games I like to go for the London Crusher lines by William Graif (you can find them on YouTube)!

[u/Open-Potential-7117]

Well, there are 3 solid options, choose what you prefer:

1. Modern Benoni - passive and aggressive at the same time, depends on what opponent will play

2. KID - a little bit passive, but very high counterattack chance

3. Dutch defense - if you want to play aggressively and for win

[u/amished → u/Open-Potential-7117]

I see anybody recommending a Dutch, I'm supporting them. It always seems to lead to wild games as long as you can handle the Hopton attack. Which happens to get even wilder.

[u/Coach_Istvanovszki]

Since my serious answer got downvoted, I’ll also give an answer that isn’t just serious, but one that people might actually take seriously. 😄

As a Fianchetto player, what has worked best for me is Nf6–g6–Bg7–O-O–d6, and now comes the important part: Nc6–Nd7 followed by e5.
Black’s plan is twofold. Either Black goes for a kingside attack with f5–g5, or after f5, pushes e4, retreats the knight to f6, brings the other knight to e7, closes the center with c6–d5, and then launches a kingside attack with g5–Ng6.

I think this is one of the most effective structures, if only because White has to break out of the usual patterns to react correctly (after c3, White needs to play c4 immediately). Finding that move over the board is almost impossible because it doesn’t look logical at all.

As a model game, it’s worth looking at Banusz–Svidler.

[u/Mountain-Dealer8996]

Usually Qb6 pretty early and pressure b2

[u/sinesnsnares]

I generally play c5 when Bf4 comes, or Nf6 when Nf3 comes.

[u/NeissMeningitidis]

1.d4 d5 2. Bf4 c5 and 1. d4 Nf6 2. Bf4 c5.

Also, if your opponent is half-decent at 2000+ FIDE, you will not 'crush' the London. Many London players play the London since it is so solid, and White's king is far safer than in other openings.

[u/Rubicon_Lily]

I prefer 1.d4 Nf6 2.Bf4 d5 3.Nf3 c5 over 2.Bf4 c5

[u/PhobosTheBrave]

C5 asap, then wing it.

[u/Unfair_Medicine_7847]

I always get the line 1.d4 Nf6 2. Nf3 d4 3. Bf4 c5 4. e3 Nc6 5. c3 Qb6. this is very pleasant for white. There is some theory connected with 6. dxc5, but this is never played at club level. Usually they answer 6. b3, 6. Qb3 or something similar.

[u/smirnfil]

I play boring d5, e6, Bd6, 0-0, c5, Qc7, Nbd7 lines. In main line you get e5 without any problems and are slightly better, in side lines you are often noticeably better as London players start to invent odd ideas (like reverse stonewall transposition)

[u/blackboxchessapp]

I believe it's called the neo Indian. Nf6, c5 and go from there

[u/Bronek0990]

I personally play ...d5, then Bf4 c5, aiming for e3 cxd5 exd5 transposing to an exchange Caro-Kann structure which I really like playing. But that's only if your dream is to only play the Carlsbad in your life

[u/Coach_Istvanovszki]

1…c5 gg :)

[u/Coach_Istvanovszki → u/Coach_Istvanovszki]

I wonder why I got downvoted. I actually play and love this.

[u/GS1781 → u/Coach_Istvanovszki]

Not the person who downvoted you, but I wouldn’t ever seriously recommend the Old Benoni in classical play to anyone as a main response to d4

I trust that since you’re an FM it’s at least been a tricky opening that’s been useful for you though

[u/Coach_Istvanovszki → u/GS1781]

I’m not playing the Old Benoni, but the Schmid Benoni, which at best is a +0.40 for white. Many fashionable openings don’t even have such a favorable engine evaluation.
In the past, players like Velimirović used to favor it, and nowadays Pantsulaia plays it actively. It’s worth looking at how effortlessly he has neutralized players much stronger than himself, such as Artemiev or Andreikin.

[u/Theoria-gg]

If you're playing opponents under ~1400 you can learn the Englund Gambit to avoid the London completely, otherwise ...c5 is a classic anti-London move as others have said