Anderssen has had a more enduring influence on chess problem composition. He started composing in the last years of the "Old School", whose compositions were fairly similar to realistic over-the-board positions and featured spectacular "key" moves, multiple sacrifices and few variations. He was one of the most skillful composers of his time, and his work forms an early stage of the "Transition Period", between the mid-1840s and the early 1860s, when many of the basic problem ideas were discovered, the requirement for game-like positions was abandoned and the introduction of composing competitions (the first of which was in 1854) forced judges to decide on what features were the most desirable in a problem.