Smitheram debuted on 21 October 1997 with victory over Scrabble player Kate Surtees who, despite losing her eighth game, held her position as No. 1 seed. All his wins were half-centuries. After losing his seventh game by one point, he returned for the quarter-finals in December as No. 3 seed but lost on a tie-break conundrum to Ruth Collier.
Smitheram is one of the world's most successful Scrabble Grandmasters, and has been playing competitive Scrabble since 1996. A former UK and World No. 1, he is the 2016 World Scrabble Champion, as well as the 2000 and 2022 National Scrabble Champion and a four-time winner of the British Matchplay Scrabble Championship. He beat Mark Nyman 3 – 0 in the final of the 2016 MSI World Championships, held in Lille, France. His second win came from 176 points behind, similar to one of Nyman's fight backs in the 1993 World Scrabble Championship final. Coincidentally, Nyman was the lexicographer at the time of Smitheram's quarter-final appearance as well as the show's producer. Smitheram was also a semi-finalist in the 2018 World Championships, losing to the eventual winner Nigel Richards. In 2020, Smitheram won the British Elimination Scrabble Tournament.
|#||Date||Type||Contestant 1||Score||Contestant 2||Presenters||Guest||Lex||Max|
|2119||21/10/1997||P||Kate Surtees||44 – 59||Brett Smitheram||Richard Whiteley||Carol Vorderman||Geoffrey Durham||Anna Eaton||81|
|2120||22/10/1997||P||Brett Smitheram||50 – 28||Sylvia Bell||Richard Whiteley||Carol Vorderman||Geoffrey Durham||Anna Eaton||73|
|2121||23/10/1997||P||Brett Smitheram||52 – 45||Colin Harwood||Richard Whiteley||Carol Vorderman||Angela Rippon||Anna Eaton||67|
|2122||24/10/1997||P||Brett Smitheram||55 – 29||Betty Cunningham||Richard Whiteley||Carol Vorderman||Angela Rippon||Anna Eaton||85|
|2123||27/10/1997||P||Brett Smitheram||53 – 31||Jonathan Goldstone||Richard Whiteley||Carol Vorderman||Angela Rippon||Anna Eaton||70|
|2124||28/10/1997||P||Brett Smitheram||59 – 52||Jeff Schwartz||Richard Whiteley||Carol Vorderman||Angela Rippon||Anna Eaton||71|
|2125||29/10/1997||P||Brett Smitheram||44 – 45||Alan Cameron||Richard Whiteley||Carol Vorderman||Angela Rippon||Anna Eaton||77|
|2158||15/12/1997||QF||Brett Smitheram||44 – 54*||Ruth Collier||Richard Whiteley||Carol Vorderman||Gyles Brandreth||Mark Nyman||84|
|S7||3/09/2003||S||Brett Smitheram||87 – 101||Harshan Lamabadusuriya||Richard Whiteley||Carol Vorderman||Richard Stilgoe||Damian Eadie||118|