In 1958, while a pupil at Kelvinside Academy, he won the Glasgow Boys' Championship with 7½/8, ahead of Gerald Bonner and T. Daly, both of St. Mungo's Academy.
Also in 1958 , Derek was 1st equal with Gerald Bonner in the Scottish Boys' Championship, each scoring 4½/5, and represented Scotland in the Glorney Cup.
The great rivalry (and friendship) with Gerald Bonner continued into 1959 when Derek shared 1st place with him in the Glasgow Boys' Championship, each scoring 7/8. A play-off match was arranged, to be played during the summer months (including an 'interruption' so that both could enter the Scottish championships). This ended in a 3-3 tie (no draws), and a sharing of the title.
In 1960, by now a member of Glasgow Chess Club, he had a busy, and successful, year. Between July 16-22 he took part in the Scottish Championship in Aberdeen, then he represented Scotland in the Glorney Cup competition in Gloucester, which was held July 26-28. Here he scored 2/3, one win and two draws on top board.
Soon after, Derek had an outstanding success when he won the the British Boys' Championship (Under-eighteen) at Leicester, August 15-27, the first Scot to do so since the competition began in 1923. He was in such good form that he had actually won the event with a round to spare, finishing with 9 points from his eleven rounds.
From Leicester, with only a few days break as can be seen, Derek headed to Whitby to take part in the 'Northern Open', held August 29 to September 9. He was less successful here, finishing well down the field with 5½, far behind the winner O'Kelly of Belgium, who ended on 10 points.
1961 was another active year for Derek. He played in the
Stevenson Memorial Tournament at Bognor Regis, April 5-15, scoring 6/11, and at the
Scottish Championships in Edinburgh, July 8-15, he scored 5/8.
Then it was off to the 1961 World Junior at The Hague, held 11 Aug - 2 Sept. Here, Derek scored 3½/6 in his preliminary qualifying group, good enough to reach the main final section. Although finishing last in this hard event, he defeated the Soviet Union's representative, Kuindzhi, who ended the tournament one point behind the winner, Bruno Parma.
In 1962 Derek played in the Scotland v England match, held April 7th. He also represented Scotland in the 9th World Student Team Chess Championship, held at Mariánské Lázne in Czechoslovakia, July 7-22. (The other members of the Scottish team were Michael Macdonald-Ross, Peter Coast, J. Wheeler and Michael Freeman, all students at Glasgow University.) Then he took part in the British Championship at Whitby, August 13-24.
Apart from the tournament results above, Derek had been involved in Glasgow League and Richardson Cup matches for Glasgow CC, but from this point on, there is a definite reduction in the number of tournaments in which Derek competed, perhaps because he was approaching the completion of his university studies. He did take part in the Scottish Championship 1963, finishing in a share of 5th-6th places with 4/7.
Derek graduated from Glasgow University in 1964, with a BSc in Maths and Natural Philosophy. (Incidentally, Ken Stewart, a particularly well known figure in Scottish chess over the years, was in the same class.) He then left Scotland and took a position with Rolls Royce in Derby from 1964-69. During this time (1968) he gained his MSc from Strathclyde University. After leaving Rolls Royce, Derek continued to live and work in England for several organisations, and married Joan in 1969.
By 1975 he had returned to Glasgow, working for Glasgow District Council in Housing Management. He became involved in chess again, initially with Glasgow CC, but later changing allegiance to the Bearsden club, as this was in the area where he lived. He played in League matches and tournaments, but his health deterioriated steadily, resulting in his need to use a wheelchair. Derek's former wife, Joan, has stated how grateful she was to the Scottish Chess Association for permitting Derek to play, even though he could not move the pieces himself. She was also grateful to those members of Bearsden Chess Club who helped Derek when he was wheelchair-bound.
Derek Thomson died shortly before what would have been his 49th birthday. The cause was motor neurone disease.
Ken Stewart estimates that at his peak playing period in the 1960's, Derek may have been rated around 2300.
Sources: Ken Stewart; Gerald Bonner; Joan Gemmell (photo, and personal reminiscences); Mel Burt (Bearsden CC).
Historian, Chess Scotland