| Genre: | Game show |
| Presenter: | David Gell (1959) Chris Howland (1960) David Gell (1960) Nick Jackson (1988) Bob Carolgees (1989–90) |
| Country: | United Kingdom |
| Language: | English |
| Num Series: | 1 (Granada era) 2 (TVS era) |
| Num Episodes: | 70 (Granada era) 23 (TVS era) |
| Runtime: | 30 minutes (inc. adverts) |
| Company: | Granada (1959–60) TVS in association with Mark Goodson Productions and Talbot Television (1988–90) |
| Channel: | ITV |
| Related: | Concentration (US version) |
Concentration originally aired from 16 June 1959 to 7 June 1960 by Granada and was initially hosted by David Gell from its inception in 1959 (Chris Howland and David Gell each hosted in 1960).
It was later revived by TVS from 4 September 1988 to 2 March 1990, hosted by Nick Jackson and Bob Carolgees.
Both versions were shown on ITV, while the American version with Alex Trebek was also shown by Sky One in the 1990s.
Two contestants sat before a game board divided up into 30 squares (25 in the TVS era). Behind each square was part of a rebus (pictures and symbols that make up a word or phrase), names of prizes, and special squares.
One at a time, the contestants called out two numbers. If the prizes or special action did not match, the opponent took a turn. However, if the contestant did match, that prize was placed on a board behind the contestant; or, he/she could perform an action. The second number had to be called out within a certain time limit, otherwise the contestant's turn ended.
More importantly, a match also revealed two pieces of the rebus. The contestant could try to solve the rebus by making one guess or choose two more numbers. There was no penalty for a wrong guess; even if he/she was wrong, he/she kept control. Usually, a contestant waited to solve the puzzle until he/she had exposed a good portion of the rebus through several matches. In rare instances, the puzzle was solved with only a few clues showing.
In 1959, each winner played up to three games. In December, the limit decreased to two. Each losing player received £10. On the TVS series, three rounds were always played no matter what the outcome, and the first to solve two puzzles won the game. Both players kept all prizes matched.
The bonus round, dubbed the "Global Game", was played for one of eight holidays. The contestant was shown a board of 15 numbered panels, behind which seven of the eight holidays had matching pairs; the eighth was always used as a decoy. Contestants were given 50 seconds (45 in series 2), and if a contestant made all seven matches, the last holiday he/she matched was the one won.
| Series | Start date | End date | Episodes | |
|---|---|---|---|---|
| 1 | 4 September 1988 | 20 November 1988 | 13 | |
| 2 | 29 December 1989 | 2 March 1990 | 10 |