Short learned chess at age five from his father. A chess prodigy, Short first attracted significant media attention as a 10-year-old, by defeating Viktor Korchnoi, then ranked No. 2 in the world, in a simultaneous exhibition in London over 31 boards, where Short was the only victor. He was virtually self-taught. In 1977 he became the youngest ever participant in the British Chess Championship by qualifying through the North West Zonal three days before his 12th birthday. In the event itself, he defeated ten-time British champion Jonathan Penrose, and finished with 5/11, an excellent showing for a debutant. Short dominated British youth chess during this period, and earned a Master rating with his showing in the 1977 British finals.