Sokolsky/Polish Opening (1.b4). Basic Opening Theory.
The Sokolsky Opening 1. b4 (also known as the Polish opening, Polish Attack, Orangutan) relates to the closed openings and is considered an irregular opening. It ranks ninth in popularity and is seldom played in top-level games and official tournaments. Thus the 1. b4 opening is another white spot in chess theory among other vaguely studied chess openings.
History of the Opening
One of the first who researched deeply into the opening was Alexey Sokolsky (1908 - 1969) - a Soviet chess player and opening theoretician of International Master strength. Sokolsky wrote a book in Russian about this opening ("Debyut 1. b2-b4", 1963) in which he gave a theoretical approach to the main ideas and variations of the 1. b4 opening. He also successfully used this opening in his games. Due to these facts the 1. b4 opening carries the name of Sokolsky. However Alexey Sokolsky wasn't the first who used this opening in official tournaments. Before him 1. b4 had been played by Hunt, Bugayev, Englisch, Schlechter and later Tartakower.
The opening is often called Polish in honor of Savielly Tartakower (who played this opening only occasionally). The most famous games in which Tartakower used this opening were a game against Géza Maróczy and a game against Richard Réti.
As for Orangutan, this funny name appeared after the game between Tartakower and Maróczy played in 1924. The day before this game the chess players visited a zoo where Tartakower asked (as a joke) an Orangutan called Suzanna what first move he should play in the coming chess battle. Some people on the Internet assume this is a rare picture of that very orangutan Tartakower and Maróczy met in the zoo:
A pensive expression on her face when Tartakower asked her what move would be better to open the game with.
The game started with 1. b4 and ended in a draw. Since then when someone calls this opening the Orangutan they usually underline their attitude towards this move as offbeat, eccentric and even jocular.
Theory of the Opening
Pushing a b-pawn two squares forward is not a random move attempting to shock your opponent with an unusual opening. The 1. b4 move creates an immediate pressure on the queenside.
In the following great game between Alekhine and Drewitt White plays b4 already on his second move! In this game Alekhine doesn't advance the b-pawn to b5 (which is so typical of the Sokolsky) but exchanges the pawns at c5.
Annotation by Alekhine
A reasonable question arises: can White start attacking on the queenside immediately without any preparation?
The main idea of 1. b4 is to gain spatial advantage on the queenside. The b4 pawn attacks the c5 square near the center; White's bishop at b2 and White's knight at f3 attack the central squares. White plans to advance the b-pawn to b5 and support it with a2-a4 and c2-c4.
Below are given the links to the most popular variations of the Sokolsky Opening as well as some rare lines. Keep tracking the main article (as well as sub-articles) so as not to miss any updates and new lines added about which I will inform you in the comments
Various continuations of the Sokolsky Opening
Popularity rank in brackets
-  Exchange Variation (1. b4 e5 2. Bb2 Bxb4 3. Bxe5)
-  Czech Defense (1. b4 e5 2. Bb2 d6)
-  Outflank Variation (1. b4 c6)
-  Main Line (1. b4 Nf6 2. Bb2 d5 (or e6 with the following d5)
-  Baltic Defense (1. b4 d5 2. Bb2 Bf5)
-  King's Indian Variation (1. b4 Nf6 2. Bb2 g6)
-  Ware Defense (1. b4 a5)
-  German Defense (1. b4 d5 2. Bb2 Qd6)
-  Bugayev Advance Variation (1. b4 e5 2. Bb2 f6 3. b5)
-  Sokolsky Gambit Accepted (1. b4 e5 2. Bb2 f6 3. e4 Bxb4)
-  Sokolsky Gambit Declined (1. b4 e5 2. Bb2 f6 3.e4 X)
-  Queen's Indian Variation (1. b4 Nf6 2. Bb2 e6 3. b5 b6)
-  Dutch Defense (1. b4 f5)
-  Advance Variation (1. b4 e5 2. Bb2 e4)
-  Birmingham Gambit (1. b4 c5)
-  Symmetrical Variation (1. b4 b5)
-  Grigorian Variation (1. b4 Nc6)
P.S. This article and sub-articles cover the basic ideas and theory of the Sokolsky opening enough to start playing this opening and handle the most popular responses by Black. For deeper learning please refer to chess books about the Sokolsky, video lessons, other chess articles and annotated games by chess masters.
А.П. Сокольский - "Дебют 1. в2-в4 (дебют Сокольского)", 1963
Y. Lapshun, N. Conticello - "Play 1. b4! Shock your opponents with the Sokolsky", 2008
J. Konikowski, M. Soszynski - "1.b4: Theory and Practice of the Sokolsky Opening", 2009