Updated: Feb 12
In the Zukertort Defense, black goes for the more active setup with the move d5. If white captures the pawn with the knight with the intention of forking the king, it is not possible as black castles queen side without allowing for white to counter and thereby giving a lead in development for black.
1.f4 e5 2.e4 exf4 3.Nc3 Nc6 4.d4 Qh4+ 5.Ke2 d5 6.Nxd5
Nxd5 does not give white much advantage as black is ready to sacrifice a pawn but if white captures with pawn then white is asking black for an immediate action from his end.
Bg4+ 7.Nf3 0-0-0 8.Bxf4 Nf6 9.Bxc7 Rxd5 10.exd5
A subtle move played which allows massive attack on the white king.
Bxf3+ 11.gxf3 Nxd4+ 12.Kd3 Kxc7 13.Qe1 Nxf3 14.Qxh4 Nxh4 15.c4 Bc5 16.Bh3 Ng6 17.Bf5 Kd6 18.Kc3 b5 19.b4 Be3 20.c5+ Kxd5 21.Rad1+ Kc6 22.Rd6+ Kc7 23.Bd3 Ne5 24.Re1 Bd2+
Giving back two pieces for a rook which does not favour black.
25.Kxd2 Nf3+ 26.Ke2 Nxe1 27.Kxe1 Rd8 28.Rxd8 Kxd8 29.Bxb5 Nd5 30.a3 a5
31.Bc4 Ne3 32.Bb3 axb4 33.axb4 f5 34.b5 f4 35.Kf2 Nf5 36.b6 Nd4 37.Ba4 g5 38.c6 Kc8 39.c7 Ne6 40.Bc2 Nxc7 41.bxc7 g4 42.Bf5+ Kxc7 43.Bxg4 Kd6
And the h pawn creates a victory path for white.
In the Fraser-Minckwitz variation,zukertort variation,paulsen defense and soerensen defense, the rule of safety of the king is violated and the king is not moved to safety. So for those players who really feel uncomfortable moving their king to safety, then this opening is not for you. Though it can be implemented while playing a blitz or a bullet game where preparation is really required while playing this game.