In shogi, the Bishop-33 opening (3ä¸Â觠san-san kaku) is an opening characterized by moving the bishop to the 33 square early while leaving the bishop diagonal opening allowing for an early bishop trade. The opening is flexible in that it can lead to an Opposing Rook (Ranging Rook) position as well as a Static Rook position with or without a bishop trade.
The most common variation and the one used by some professional players is the Fourth Move Bishop-33 opening (4æÂÂç®3ä¸Âè§Âæ¦泠yon-teme san-san kaku senpà Â). When used by Black, this is known as Third Move Bishop-77 opening (3æÂÂç®7ä¸Âè§Âæ¦泠san-teme nana-nana kaku senpà Â).
1. P-76 P-34, 2. P-26.
2...B-33. White's bishop moves to the 33 square on the fourth move of the game keeping their bishop diagonal open.
This move invites Black to capture the bishop which is only defended by White's left knight.