Barnes Opening (A00)

Barnes Opening (or Gedult's Opening) is a chess opening where White opens with: 1. f3

The opening is named after Thomas Wilson Barnes (1825–74), an English player who had an impressive eight wins over Paul Morphy, including one game where Barnes answered 1.e4 with 1...f6, known as Barnes Defence.

Of the twenty possible first moves in chess, author and grandmaster Edmar Mednis argues that 1.f3 is the worst. The move does exert influence over the central square e4, but the same or more ambitious goals can be achieved with almost any other first move. The move 1.f3 does not develop a piece, opens no lines for pieces, and actually hinders the development of White's king knight by denying it its most natural square f3. It also weakens White's kingside pawn structure, opens the e1–h4 diagonal against White's uncastled king, and opens the g1–a7 diagonal against White's potential kingside castling position.

Barnes Opening can lead to Fool's mate, 1.f3 e5 2.g4 Qh4 mate. Of all of White's legal moves on his second move, only one allows mate in one, while another, 2.h3, allows mate in two.

David Gedult, a cult hero of the Blackmar-Diemer Gambit community, often played 1.f3 d5 2.e4 dxe4 3.Nc3. This is sometimes called the Gedult Opening. Play often transposes to the Blackmar-Diemer Gambit proper, with 3...exf3 4.Nxf3 Nf6 5.d4.