Kf1?! line in petrov

1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Bd6 7. c4 Bb4+ 8. Kf1?!

i saw this move in game by Janowski - Marshall (1912) in Janowski - Marshall Match 4 rd 3, and im really confused about it.

8.Nbd2 develops a piece, and 0-0 followed up by Nxe4 would be a threat. while it is true that the d2N isnt placed in ideal spot, however black is half a tempo down by the move Bb4+, and white also has the plan to kick away the bishop by a3 and eventual Nxd4 removing the powerful piece by opponent from the board.

while the masters database agrees with me, somehow this bizzare move Kb1 is almost played often as the move Nbd2. Kb1 hinders the development of the h-file R and the king is unsafe (in fact Marshall won this game by exploiting this positional weakness).

however this move avoids piece exchange which is kind of reasonable in potential IQP position, but that comes down to the question of why did white played c4 in the first place, considering the fact that the position is inferior compared to the normal IQP position because of the absence of e6 pawn.

i would like to hear your opinion about this move.

I agree with you. As I am sure you already know, Stockfish also agrees with you. Janowski was a strong player - why did he make this junky-looking move? That is the question, for which we will probably never know the answer.

@ambrooks said in #2:
> I agree with you. As I am sure you already know, Stockfish also agrees with you. Janowski was a strong player - why did he make this junky-looking move? That is the question, for which we will probably never know the answer.

We will likely never know for sure, but I think the answer is that Janowski wanted to avoid simplifications. He was a very courageous player always looking for a fight. BTW, one year later Janowski actually played 8.Nbd2 against Marshall, he had learned his lesson after getting crushed in the above game.

@zwenna "but I think the answer is that Janowski wanted to avoid simplifications"
That's better than any answer I can come up with. Let's go with that.

the most mysterious part is that like i said this is the move that is employed by the masters and is somehow the second popular move and the frequency is very close to the first popular one Nbd2.

i know 11 games isnt enough to do a statistical analysis but the masters database shows Kf1 the higher win rate than Nbd2......

@Cs1xlly said in #1:
> Kb1 hinders the development of the h-file R and the king is unsafe

Kb1 is a typo, isn't it?

Looking at some games in the database, it seems after Kf1 you can develop the Rook and attack pushing the h-pawn, or getting the King behind f2-g3-h3 pawns. It looks weird but it works, I guess...