London System: Dealing with ...Bg4

London System: Dealing with ...Bg4

May 15, 2018, 11:53 PM |

Two weeks ago we looked at White's best play when Black plays the copycat with ...Bf5 (see here). In the meantime I visited London for some philosophy, but now it's time to look at another way in which Black can surprise White: by playing the much rarer ...Bg4

White's strategy here is a bit more varied, but the ideas are similar as against ...Bf5:

1. Try to hunt down or at least harrass the bishop, this time with either f3 or h3 (and perhaps g4-h4-h5 or Nh4) or Ne5

2. Exploit the absence of the bishop from the Queenside with c4 and Qb3 to put pressure on b7 (much like Black tries c5 and Qb6 to put pressure on b2)

1. Black plays Reversed Pseudo-Tromp style with 2...Bg4 or with 2...Nf6 & 3...Bg4

As before, Black could develop the bishop on the 2nd move, even though it's super rare. Here Sedlak suggests playing in the Jobava Attack style with 3. Nc3:

Black could also play 2...Nf6 and upon seeing 3. e3, attack the Queen with 3...Bg4. This is quite common at amateur level and reminiscent of the Portuguese Scandinavian. If White is to get an advantage he needs to react with 4. f3. It's therefore a bit surprising that only Johnsen & Kovacevic and Romero & Prado mention this line while neither Lakdawala nor Sedlak have anything to say about it at all:

Here's Carlsen defeating Judit Polgar in a crazy blitz game in one of these lines:

2. Black plays the Chigorin with 2...Nc6, 3...Nf6 and 4...Bg4

Black could play the Chigorin with ...Bg4. Here White can choose between prodding it immediately with 5. h3, counterpinning with 5. Bb5, or playing 5. c4, all of which are good:

3. Black plays Qb6-c4-Bg4!?

Black could play the same Qb6-c4 line, but instead of trying to bring out the bishop by tactical means he could go for Nf6 & Bg4. Here the best plan is to not pay attention to it at all and instead play immediately for the b3 & e4 breaks that are necessary after Black has played c4.

4. Black plays the Exchange Caro with 5...Bg4

Black could play c5, exchange on d4, and then play ...Bg4. Here the plan is Qb3, Nf3, Bd3, 0-0, and then Ne5 to harrass the bishop:

Here's Walter Browne defeating Bent Larsen in this line:

5. Black plays Classically in QG Style with ...Bg4

Finally, Black could play c5, but keep the tension and play ...Bg4. The ideas and even moves are the thematic Qb3 and Nh4: