Glossary of Chess Problems - T

T

Task

A highly unusual or bizarre theme, e.g. Babson-task or Valladao-task.

Theme

The underlying idea of a problem, which gives it logic, coherence and beauty.

Threat

A move or variation which white will play (usually following his key) if black does nothing to defend against it. Problems which do not have threats following the key are blocks.

Three-mover

A problem with the stipulation "white to move and checkmate black in no more than three moves against any defence". In composition tourneys, there are often separate classes for three-movers, two-movers and more-movers (as well as classes for helpmates, selfmates and others).

Try

A move which almost solves a problem, but is defeated by a single black defence, as opposed to the key (which actually does solve the problem). Variations after tries are called virtual play and may be an important part of what makes some problems pleasing.

Turton doubling

A kind of doubling in which one piece moves along a line allowing a second to move onto the same line in front of it; this second piece then moves in the opposite direction to the first. Named after Henry Turton. Compare with Zepler doubling.

Twin

Two or more problems which are slight variations on each other, composed by the same person. The variation is usually brought about by adding, removing or moving a piece in the initial setup.

Two-mover

A problem with the stipulation "white to move and checkmate black in two moves against any defence". In composition tourneys, there are often separate classes for two-movers, three-movers and more-movers (as well as classes for helpmates, selfmates and others).