Introduction to 1. Nh3

1. Nh3 aims at attacking the Black king quickly like 1. Nf3, but it's lines are much different than the 1. Nf3 lines. White's immediate threat is 2. Ng5 and then 3. Nf7. The following nine moves do not address this threat and all lose to 2. Ng5 f6 (or f5) 3. Nf7: 1. ... a5??, 1. ... a6??, 1. ... b6??, 1. ... b5??, 1. ... g6??, 1. ... h5??, 1. ... Na6??, 1. ... Nc6??, 1. ... Nh6??. For example: 1. Nh3 a6 2. Ng5 f6 3. Nf7 and now White will play 4. Nxd8## next. The following move is even worse than these: 1. ... Nf6??. In this case, 2. Ng5 followed by 3. Nxf7## wins even quicker.

Out of all moves that might hinder the advance of White's knight, 1. ... g5 might appear at first glance to be the most logical since it stops both 2. Ng5 and 2. Nf4. Unfortunately, 1. ... g5?? gives White a forced short win. The reason is that this move weakens the h5-e8 diagonal leading to the Black king, and White will take advantage of this with his queen. White proceeds with 2. e3, threatening 3. Qh5. Black has no defense. Here are some tries:

(A) 2. ... h5 3. Qf3 Nf6 (3. ... f6 (or f5) 4. Qd5 [1-0]) 4. Nxg5 f6 (or f5) 5. Qd5 [1-0]. White is forking d7 and f7.

(B) 2. ... Nf6 3. Nxg5. Now, either 3. ... h5 4. Qf3 f6 (or f5) 5. Qd5 [1-0] or 3. ... Rg8 4. Qh5 (4.Qf3? Rxg2) Rg6 5. Qd5 [1-0] or 3. ... d6 (or d5) 4. Qh5 kd7 5. Qf5+ [1-0]

(D) 2. ... d5 3. Qh5 Kd7 4. Bb5+ Kd6 5. Qf3 d4 6. Qd5#

So far, that's 11 of Black's 20 legal first moves. They all result in quick wins for White. The other 9 moves do not give White quick forced wins, but some of them are clearly bad. We address these next. 1. ... d6? is just as bad after 1. Nh3 as it is after 1. Nf3: 1. Nh3 d6 2. Ng5 f6 (or f5) (2. ... Kd7?? 3. Ne6 [1-0]) 3. Nf7 Qd7 4. Nxd6 [+-]. Similarly, 1. ... d5? loses the Black queen: 2. Ng5 f6 (or f5) 3. Nf7, and now 3. ... Qd7 leads to 4. Nd6+ Qxd6 [+-] and 3. ... Qd6 4. Nxd6 [+-] is only better by a mere tempo.

Another move that deserves a question mark is 1. ... c5?. This move gives an escape route to the Black queen in case the White knight lands on f7, but it just gives White material: 2. Ng5 f6 (or f5) 3. Nxh7 [+-]. Now Black has no couterattack with the Black queen.

An improvement to the last move is 1. ... c6?! I believe Yokke invented this response at FICS and has more than 100 games with it in wildchess.org. We may look at this opening in more detail later, but let's look at a few moves now. White can proceed with 2. Ng5 f6, and now let's see what happens after 3. Nxh7: 3. ... Qa5 4. c3 Qf5 (forking f2 and c2) 5. f3 Qc2 6. Qxc2 [+=]. Black has recovered some material and has good drawing chances. White is up the equivalent of an exchange (rook for minor piece). White can probably improve on this line, however. For example, instead of taking with 3. Nxh7, White can increase the pressure with 3. e3 since then 3. ... fxg5? leads to 4. Qh5+ g6 5. Qe5 e6 6. Qc7 Qxc7 [+-]. I'll leave further theory after 3. e3 to another time. Also, White might even try 1. Nh3 c6 2. e3, combining queen and knight threats. Both 2. e3 and 3. e3 seem to be hard for Black to handle.

After 1. Nh3, Black also has an option to enter a Vlasov or similar position (which normally arises after 1. Nf3 e5 2. Ng5 f5). For example, 1. ... e5?! can lead to 2. Ng5 f5 [+=]. Or 1. ... e6 can lead to 2. Ng5 f5 [+=]. This last line deserves exploration since it is slightly different than the normal Vlasov position with the pawn on e6 instead of e5. Yet another similar possibility is 1. ... f5 after which White can transpose with 2. Ng5 e5 (or e6) [+=], or can try something like 2. Nf4 and Black has to contend with the knight coming to h5 or d5.

So far we have talked about 18 of 20 legal responses to 1. Nh3 and none of them seem good. This leaves only two moves. Fortunately these last two moves are far superior. First, consider 1. ... f6 (you were probably waiting for me to say that). This keeps the knight off of g5 and if 2. Nf4 then Black has a clever defensive move. 2. Nf4 is tempting because the knight threatens further advancement to either d5 or h5. How can Black stop both of these advances? With 2. ... d5! This keeps the knight off of d5 and now if 3. Nh5 then 3. ... Bg4 4. f3 Bxh5 [=] for a roughly equal game. So, after 1. Nf3 f6 White usually tries something else like the very common 2. Nc3 c6 3. e3. White now has threats utilizing the queen and knight sacrifices (not to mention the move Bd3). This position is considered to be hard for Black to defend and as far as I know, Black has to give up a pawn. This is why the last of our 20 moves to be considered is played much more often (at least nowadays and at least among top players).

We're down to 1. ... h6. It's funny that this surprising little move is considered best amongst most top players (at the time of writing, of course). One of the reason it is believed to be superior to 1. ... f6 is that now if 2. Nc3, Black doesn't have to play 2. ... c6. He also has the option of 2. ... e6 with the idea that if 3. Nb5 then out comes the queen: 3. ... Qh4 with complications to ensue. Thus, 1. ... f6 blocks this possible queen manouver. In addition to 2. Nc3, White also commonly plays (more commonly, in fact) 2. e3 and then 2. ... e6 is the usual response. There is much known theory after that which we will explore later. Other common moves are 2. e4 and 2. d4, and of course 2. Nf4 can be met as discussed earlier: 2. ... d5! 3. Nh5 Bg4 4. f3 Bxh5 [=].

So, in summary, after 1. Nh3, 11 of Black's 20 legal responses lose immediately, 3 moves lead to uncompensated loss of material, 4 moves lead to questionable positions (including vlasov-type positions), and of the remaining two moves, both (1. ... f6 and 1. ... h6) are playable, but top players seem to highly prefer one of them (1. ... h6).


KEY: 
When branching occurs, move options are listed
from best to worst according to the author's opinion.
# = mate
## = win by explosion
? = bad move
?? = loses to a short forced mate
?! = probably a bad move
other marks are standard chess notations

1. Nh3
  1. ... h6
    2. e3 e6
    2. Nc3 e6 3. Nb5 Qh4
    2. e4
    2. d4
    2. Nf4 d5! 3. Nh5 Bg4 4. f3 Bxh5 [=]
  1. ... f6
    2. Nc3 c6 3. e3
    2. Nf4 d5! 3. Nh5 Bg4 4. f3 Bxh5 [=]
  1. ... c6?!
    2. Ng5 f6 
      3. Nxh7 Qa5 4. c3 Qf5 5. f6 Qc2 6. Qxc2 [+=]
      3. e3 fxg5? 4. Qh5+ g6 5. Qe5 e6 6. Qc7 Qxc7 [+-]
    2. e3
  1. ... e6?! 2. Ng5 f5
  1. ... e5?! 2. Ng5 f5
  1. ... f5?!
    2. Nf4
    2. Ng5
      2. ... e6
      2. ... e5
  1. ... c5? 2. Ng5 f6 (or f5) 3. Nxh7 [+-]
  1. ... d5? 2. Ng5 
    2. ... f6 (or f5) 3. Nf7 
      3. ... Qd6 4. Nxd6 [+-]
      3. ... Qd7 4. Nd6+ Qxd6 [+-]
    2. ... Kd7?? 3. Ne6 [1-0]
  1. ... d6? 2. Ng5
    2. ... f6 (or f5) 3. Nf7 Qd7 4. Nxd6 [+-]
    2. ... Kd7?? Ne6 [1-0]
  1. ... g5?? 2. e3
    2. ... h5 3. Qf3
      3. ... Nf6 4. Nxg5 f6 (or f5) 5. Qd5 [1-0]
      3. ... f6 (or f5) 4. Qd5 [1-0]
    2. ... Nf6 3. Nxg5
      3. ... Rg8 4. Qh5 Rg6 5. Qd5 [1-0]
      3. ... h5 4. Qf3 f6 (or f5) 5. Qd5 [1-0]
      3. ... d6 (or d5) 4. Qh5 Kd7 5. Qf5+ [1-0]
    2. ... d6 3. Qh5 Kd7 4. Bb5+ [1-0]
    2. ... d5 3. Qh5 Kd7 4. Bb5+ Kd6 5. Qf3 d4 6. Qd5#
  1. ... a6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... a5?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... b6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... b5?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... g6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... h5?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... Na6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... Nc6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... Nh6?? 2. Ng5 f6 (or f5) 3. Nf7 [1-0]
  1. ... Nf6?? 2. Ng5 [1-0]