The Babson task is a special form of Allumwandlung, a chess problem in which the solution contains promotions to each of the four possible pieces.
This 1912 problem by Wolfgang Pauly is, as it were, a three-quarter Babson task: three of Black's promotions are matched by White.
Composing a Babson task in directmate form (where White moves first and must checkmate Black against any defence within a stipulated number of moves) was thought so difficult that very little effort was put into it until the 1960s, when Pierre Drumare began his work on the problem, which occupied him for the next twenty years or so.
Efficiency in chess problems is considered a great boon, but Drumare's attempt is very inefficient: no fewer than 30 pieces are on the board.
It also has six promoted pieces in the initial position (even a single promoted piece is considered something of a "cheat" in chess problems), which is in any case illegal: one of the white f-pawns must have made a capture, and the white and black b- and c-pawns must have made two captures between them, making three in total, yet only two units are missing from the board.
First published in March 1983 in the famous Russian chess magazine Shakhmaty v SSSR, this is generally thought of as the first satisfactory solution of the Babson task.
Also, when first presented, the black piece at h4 was a pawn, but a computer discovered an additional solution by 1.axb8=N hxg3+ 2.Kh3 Bxb8 3.Qxc2 and mate next move.
Nevertheless, when Dutch author Tim Krabbé saw this version in the Soviet publication 64, he records that the realisation that somebody had at last solved the Babson task had the effect upon him as if he had "... opened a newspaper and seen the headline 'Purpose Of Life Discovered'."
Yarosh continued to work on the problem, and in August 1983, he created an improved version with a non-capturing key, which appeared in Shakhmaty v SSSR.
In the September 2005 issue of Schach [de], the first cyclic Babson without promoted pieces in the initial position was published.
The thematic defences are: Achieving a Babson Task in an endgame study was for long time considered impossible, because of the enormous complexity requested to make every promotion the only winning move, avoiding duals and keeping the position legal.
Some partial Babsons have been showed in form of a study, but at maximum 3/4 of the theme was achieved (usually missing the Rook variation).
The composer declared to have worked on that position for more than 13 years, trying to make it legal, but eventually giving up and publishing it anyway, out of competition.
[5] In January 2025, again on EG, the Italian chess composer Daniele Guglielmo Gatti showed a complete Babson Task in an endgame study.
This made him effectively the first composer in history to correctly achieve the task in an endgame study, 141 years after the theme was proposed by his eponym.