Is this a good way to counter London System! !?

1. d4 - Nf6

2. Bf4 - Nh5 !

I know it's not the best way, but certainly most surprising way ! 

What's black plan here ? Do they just create a mess from the opening and rely to outplay an opponent in a middle game?  Or theirs some system here, like casting long here etc..

Move order matters.  But I get great results with the following:  1.d4 Nf6 2.Bf4 g6 3.e3 Bg7 4.Nf3 d6 5.h3 O-O 6.Nbd2 Nbd7 7.Be2 Qe8 8.O-O e5 9.Bh2 Qe7.

Now if White does not do an early Nbd2, like 1.d4 Nf6 2.Bf4 g6 3.e3 Bg7 4.Nf3 d6 5.h3 O-O 6.Be2 Nbd7 7.O-O, then Black can accelerate the process and save a move with 7...Ne4! 8.Nbd2 Nxd2 9.Qxd2 e5 (now the Bishop is the 3rd piece to cover e5) followed by ...Qe7, obviously responding to any trades on e5 first, but if the immediate Bishop retreat, then 10...Qe7.

Now admittedly, this falls in line with of style of a King's Indian Defense player, but if you play the QGD or Slav or other 1...d5 defenses, or the Nimzo, where you do not typically fianchetto the kingside, then this may not be for you.

Guys please stay on topic , I'm asking about particular scenario which I mentioned above.

Well, I tried to help you, but if that's going to be your attitude, then the simple, blunt answer is NO!  2...Nh5 is utter crap!

Crap?  How so ?  

King's Gambit crap as well , yet Ian Neponitchia played it in classical .

And I'm not planning on playing classical or with GMs .

2... Nh5 is bad because (a) it moves a piece twice in the opening, but does not improve the positioning of that piece, (b) it is easily met with 3. Bg5 or 3. Bd2, when white's dark-squared bishop is more useful than black's h5-knight, (c) the knight likely will have to reenter the game via f6 anyway, which would mean that black wasted two tempi in the opening, and (d) the knight on h5 is loose, which means that white will be able to play e3 with tempo at some point in the future (the queen on d1 will have line-of-sight with the knight on h5). The move is bad because it just wastes time for black while providing no particular inconvenience for white. The only reason white is not in a crushing position after 2... Nh5 is because white chose to play a London, which does not put much pressure on black's position right out of the opening.

That said, I'm guessing that you can get away with playing 2... Nh5 until probably 2100, just because I would guess that people up to 2100 won't be able to do much with "slight advantage out of the opening." So, if you enjoy playing 2... Nh5, you probably won't lose too many games because of it. But it isn't a "good" way to counter the London by any means.

...Then again, looking at your profile, you are 2100 in Rapid, so maybe you let us know how 2... Nh5 works out at your level.

As for plans, I ran through a few lines, and it looks like Stockfish likes moves like ...g6 (to protect the knight), ...Bg7, ...c5, and ...Qb6, attacking the central dark squares, and trying to make the g7-bishop good. It's possible you can play this like a King's Indian and play ...f5, expanding on the kingside while the knight is out of the way, if white's not paying attention.

King's Gambit is fine.

Please stay on topic

Believe it or not, I actually seriously considered this before! And I concluded that no, while not terrible, doesn’t really work. For example- Bc1. Then I suppose black could draw with Nf6 Bf4 Nh5 Bc1 Nf6… other options just don’t inspire confidence. I think it’s playable at best.

@busterlark the bishop is often misplaced on d2 in QP openings. The bogo indian takes this to an extreme, and I suppose after Bd2 black can play Nf6, arguing that the bishop on d2 justifies the extra tempo.

In the case of Bg5 simply h6. I think that black can play g5 after Bh4, which is probably still better for white, though. 

I think that after Nh5 the best move is Bg5, h6, then Bh4- it’s too early to weaken the kingside, although sometimes white does it in the Slav. (G4). I think black should play g5, otherwise his last moves don’t make sense. After g5 Bg3 Bg7  e4 Nxg3 hxg3 d6 white is definitely better- he will castle queenside and attack the king.

So maybe g5 isn’t good, but I’m a bit iffy. Black can try Bg5 g6, when g4 feels positionally unsound. I think he can definitely play this, but white gets a comfortable game after Bg5.

No:

Black plays Nf6 and he is ok. The dark squares bishop doesn’t really want to be on d2. Alternatively black can play Nf6 instead of d5, and what does white do with the creature on d2? 

lol you are right.  Though I checked in an engine it said Bd2 after Nh5… Kinda cute place for the bishop

lol

The engine on lichess calls the modern defense a mistake

Wait what… I will check with the engine again what tells…

Dealing with Nh5 (at any point) is part of most London players' prep. It would not surprise them at all, unfortunately.

Now black's best move is to retreat the knight back to f6, admitting his mistake. White then repositions the bishop to g3.

The result is that black has weakened his kingside, so any future kingside castling would come at a risk ...

Nh5 can be a viable move, yes. But it's usually more profitable at the later stages of the opening, or in the beginning of the middlegame (if white allows it).

It changed it’s mind to Bg5, but another engine says Bd2