Sokolsky’s Opening is an opening in chess, namely the move 1. b4. It’s also known as the Orangutan Opening or Polish Opening.

In the Encyclopaedia of Chess Openings it holds the code A00. According to the Lichess database, across all Elo ratings (1600–2500) and all time controls, the most common responses are:

Who was Sokolsky?

Alexey Pavlovich Sokolsky (1908–1969) was a Ukranian-Belarusian International Master who developed this particular opening, (Wikipedia contributors 2019a) to the point of writing an entire book about it. (Sokolsky 2016)

Why ‘Polish’? Why ‘Orangutan’?

According to some sources, it’s in honor of Savielly Tartakower,(Eugen R 2014) an Austrian, then Polish, then French chess Grandmaster.¹ Allegedly, Tartakower was visiting a zoo the day before a match against Géza Maróczy in New York. He either admired an Orangutan or jokingly asked it for the best opening for the upcoming match. (Wikipedia contributors 2019b) The game is as follows, in PGN format

An Orangutan-suggested opening

[Event "Tartakower Savielly vs Maroczy Geza (1924)"]
[Site "https://lichess.org/a65bN6OJ"]
[Date "1924.03.21"]
[Round "4"]
[White "Tartakower, Savielly "]
[Black "Maroczy, Geza "]
[Result "1/2-1/2"]
[ECO "A00"]
[Opening "Polish Opening: Schiffler-Sokolsky Variation"]
[Termination "Normal"]
[Annotator "lichess.org"]

1. b4 e6 2. Bb2 Nf6 3. b5 d5 4. e3 { A00 Polish Opening: Schiffler-Sokolsky 
Variation } Be7 5. f4 O-O 6. Bd3 a6 7. a4 axb5 8. axb5 Rxa1 9. Bxa1 Nbd7 10. 
Nf3 Ne4 11. O-O f5 12. Be2 Nd6 13. Qc1 Bf6 14. Na3 c6 15. bxc6 bxc6 16. Ne5 
Bxe5 17. fxe5 Nf7 18. d4 Ng5 19. c4 Ba6 20. Re1 Qa8 21. Bc3 Rb8 22. Qc2 Ne4 
23. Bd3 Rb7 24. Rc1 Nb6 25. Be1 h6 26. Bxe4?! { (-0.06 → -0.79) Inaccuracy. 
Best move was Bf1. } (26. Bf1 Qf8 27. Ra1 c5 28. Nb5 Bxb5 29. cxb5 c4 30. 
Be2 Qe8 31. Qb2 Rc7 32. Ra6 c3 33. Bxc3 Rxc3 34. Rxb6 Rxe3) 26... dxe4? { 
(-0.79 → 0.27) Mistake. Best move was fxe4. } (26... fxe4 27. Bb4 Nxc4 28. 
Nxc4 Bxc4 29. Bc5 Bd3 30. Qf2 Rf7 31. Qd2 Qd8 32. Kh1 Qh4 33. Kg1 Qg4 34. 
Kh1 Qh5 35. Ra1 Kh7 36. Bd6) 27. Qc3 Nd7 28. Rb1?! { (0.20 → -0.37) 
Inaccuracy. Best move was Ra1. } (28. Ra1 Ra7 29. Nc2 Bb7 30. Rb1 Bc8 31. d5 
c5 32. Bg3 Ra6 33. dxe6 Rxe6 34. Rf1 g6 35. Na3 Ba6 36. Rd1 Qc6 37. Rd6 
Rxd6) 28... Rxb1 29. Nxb1 Qb7 30. Na3 Qb6 31. Bd2 Kf7 32. g3?! { (0.00 → 
-0.64) Inaccuracy. Best move was c5. } (32. c5 Qb8 33. Qc1 Qb3 34. Nc2 g5 
35. Nb4 Bb5 36. Kf2 h5 37. Qc2 Qxc2 38. Nxc2 h4 39. Ba5 Ke7 40. Bd2 Kf7) 
32... Nf8?! { (-0.64 → 0.00) Inaccuracy. Best move was c5. } (32... c5 33. 
Kg2 Qc6 34. Be1 Qa4 35. dxc5 Nxc5 36. Qa5 Qc6 37. Nb5 Nd3 38. Bc3 Bxb5 39. 
cxb5 Qc5 40. Bd4 Qc2+ 41. Kh3 Nf2+ 42. Kh4) 33. Qb4 Qxb4 34. Bxb4 Nd7 35. 
Ba5 g5 36. Kf2 Ke8 37. Ke2 c5 38. Nb5 Kf7 39. Kd2 cxd4 40. exd4 f4 41. Nd6+ 
Kg6 42. Kc3 e3 43. Kd3 Nb8 44. Ke4 Nc6 45. Bc3 e2 46. gxf4 gxf4 47. Bd2 f3 
48. Kxf3 Nxd4+ 49. Ke3 Nf5+ 50. Kxe2 Nxd6 51. exd6 Bxc4+ 52. Ke3 Bb5 53. Kd4 
h5 54. Kc5 Ba4 55. Kb6 Kf7 56. Kc7 Ke8 57. Bf4 { The game is a draw. } 1/2-1/2

According to (a version of) Stockfish10, the game in general had:

For White

3 inaccuracies, namely 26. Bxe4?!, 28. Rb1?! and 32. g3?!

for Black

1 inaccuracy, namely 32... Nf8?!

1 mistake, namely 26... dx34?!

Continuations to Sokolsky’s Opening

As rated by chess.com:

Further reading

(Unreviewed by this writeup’s author)

• «Play 1 b4! : Shock Your Opponents with the Sokolsky» (Conticello and Lapshun 2008)
• «1.b4: Theory and Practice of The Sokolsky Opening» (Konikowsky 2009)

References

Conticello, Nick, and Yury Lapshun. 2008. Play 1 B4! : Shock Your Opponents with the Sokolsky. Everyman Chess. https://www.ebook.de/de/product/7074923/nick_conticello_play_1b4.html.

Eugen R. 2014. “Sokolsky/Polish Opening (1.b4). Basic Opening Theory.‎.” Edited by chess.com. November 14, 2014. https://www.chess.com/article/view/sokolskypolish-opening-1b4-basic-opening-theory2.

Konikowsky, Jerzy. 2009. 1.b4: Theory and Practice of the Sokolsky Opening. Russell Enterprises, Incorporated. https://www.barnesandnoble.com/w/1b4-jerzy-konikowsky/1112228647.

Sokolsky, Alexey. 2016. Sokolski Debut 1. B2-B4. Ishi Press. https://www.ebook.de/de/product/28112148/alexey_sokolsky_sokolski_debut_1_b2_b4.html.

Wikipedia contributors. 2019a. “Alexey Sokolsky — Wikipedia, the Free Encyclopedia.” https://en.wikipedia.org/w/index.php?title=Alexey_Sokolsky&oldid=921924300.

———. 2019b. “Savielly Tartakower — Wikipedia, the Free Encyclopedia.” https://en.wikipedia.org/w/index.php?title=Savielly_Tartakower&oldid=932835411.

1. I swear, this is how it says on the article.