sentences:  The heats were presented by Tess Daly, and the grand final by Carol Vorderman again.There was also a format change in 2002, with tie breakers being replaced by "Codexs" after the mammoth tie-break in the 2001 show.There were also several spin off shows, such as "Britain's Brainiest Footballer" and "Britain's Brainiest Cabbie" after the success of the 2001 show.