Ajedrez y negocios

Introduction
The Halloween Gambit was already known by Oskar Cordel in 1888 who pointed to the formidable attacking possibilities  in his « Fuerher der Eroeffnungstheorie «  but  concluded that this finally was not worth the sacrifice.
In that time the gambit was called the Mueller-Schultze gambit, but Rainer Schlenker, well known by all Unorthodox chess lovers, re-baptized it as the HalloweenGambit in his magazine « Randspringer » in December 1993.  The name is founded on the fact that players who are for the first time confronted with the surprising and unexpected fourth move of white become so shocked as if they were suddenly confronted with the horror of some scary Halloween mask.
Indeed, this fourth move is shocking. After : 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 when  Black is expecting anormal Four Knights Game move as 4.Bb5, White surprisingly takes the pawn on e5 (diagram).
A certain Steffen A. Jakob, German chessplayer and computer programmer was heavily touched by the Randspringer article and created Brause.  Brause was a clone of the chess program Crafty loaded with a Halloween gambit opening book and played more than 3000 internet games in the period from 1996 to 1998 inwhich it scored 72 %. Jakob constantly changed and improved the opening book of Brause up to more than 500 sub-variations.
Brause showed in a lot of short games how deadly  this gambit could be.  One example : 1.e4 e5 2.Nf3 Nc6 3.Nc3 Nf6 4.Nxe5 Nxe5 5.d4 Nc6 (this is one main line, the other one is 5 ..Ng6),  6.d5 Nb8 7.e5 Ng8 8.d6 c6 9.Bc4 f6 10.Qh5+ g6 11.exf6 Qxf6 12.Qe2+ Kd8 13.Ne4  and Blackresigned Brause (2355)-Betrueger (2315),ICC,1997,1-0(13).
In these days  the theory of the Halloween gambit knows a second revival due to new analyses of Maurits Wind and to the extended power of chess programs as Fritz and Hiarcs. 
This article is in large part based on an extended analysis by FM Maurits Wind which is going to appear in the German magazine Kaissiber nr 20, an article whichwill be very interesting for all Halloween fans.
In this article I want to summarize the lines I have met most frequently while playing this gambit, and how to handle so-called refutations and critical lines.

Model game
1.Nc3
The preparation part : the Queens pawn opening is the best way trying to reach the Halloween. Via e2-e4 it’s  more difficult : black has more ways to deviate (Sicilian,Caro-Kann, etc.)
1...e5
2.e4 Nf6
3.Nf3 Nc6
4.Nxe5?!
Here the fun starts!
4...Nxe5
What does White get for the piece?  A pawn and the center.  Not enough? Let's try it out.
5.d4
Now we are in the second and most amusing part : the hunt for the Knights. The following White moves are not hard to find.
5...Nc6
Ng6 is the other main line.
6.d5 Ne5
7.f4 Ng6
8.e5 Ng8
The third part of thegame : searching for combinations. White has the center, and his bishops are free to run.  If there was not the loss of the piece, White would already  have a superior position.  The strategy is : try to hamper Black's development while attacking, and look for a way to get definitive advantage.
9.d6
Now after cxd6 exd6  White is menacing Qe2 to win back the piece with the better pawnstructure.9...a6
Black is afraid of the manoeuvre Nc3-Nb5-Nc7.
10.h4
The queenside defended by a6 ? No problem, the point of attack will be  switched to the kingside. There still is a knight waiting for us.
10...cxd6
11.exd6 Qf6
12.Qe2+ Kd8
13.Nd5
What follows is typical play in this kind of position.
13...Qxd6
14.Be3
14...Qxd5 being impossible because of 15. Bb6+ and the game is over
14...Nxf4Black decides to give the piece back, but he still is vulnerable : pawn d7 is isolated and the King has to stay in the middle.
15.Nxf4
Fourth part of the game : trying to win a won position.
15...Ne7
16.Nd3 Nd5
17.0-0-0 Nxe3
18.Qxe3 Qe6
19.Qd4 Qxa2
20.Qb6+ Ke8
21.Re1+ Be7
22.Nb4
With Nd5 in the air.
22...Qa1+
23.Kd2 Qxe1+
24.Kxe1 h5
25.Nd5 Rh6
26.Nc7+ Kf8
27.Nxa8 Rxb6
28.Nxb6...