He won two games unbeaten in Series 56, but had to retire for personal reasons without losing a game. The producers allowed him to continue his run in Series 57 where by chance he faced seven-time winner Mikey Lear. The game was close throughout, but May avoided a crucial conundrum by spotting DUSTIER in the last letters round. May went on to win three more games before losing to Steve Baines who would by coincidence also go on to win 7 games and lose the final 8th one.
In January 2010, May attended his first unofficial Countdown tournament, COLIN 2010 where he managed an impressive 5th place.
May re-appeared on the show in Series 79. He started his run against Paul Hollidge with a strong 96 points win. He then went on to achieve four consecutive centuries during his heat run, totalling six in total. He spotted impressive nine letter findings such as NORMALISE and RESHAPING. May rounded off his Series 79 run with a total of 839 points to become the number one seed of the series.
|#||Date||Type||Contestant 1||Score||Contestant 2||Guest||Lex||Max|
|4282||29/01/2007||P||Leigh Brook||67 – 86||Martin May||Gyles Brandreth||Susie Dent||129|
|4283||30/01/2007||P||Martin May||95 – 84||Daniel Giddings||Gyles Brandreth||Susie Dent||141|
|4412||9/08/2007||P||Mikey Lear||70 – 97||Martin May||Ann Widdecombe||Susie Dent||115|
|4413||10/08/2007||P||Martin May||90 – 81||Gina McDowell||Ann Widdecombe||Susie Dent||131|
|4414||13/08/2007||P||Martin May||104 – 68||Patrick Durnall||Ann Widdecombe||Susie Dent||118|
|4415||14/08/2007||P||Martin May||101 – 79||Amanda Vickery||Ricky Tomlinson||Susie Dent||131|
|4416||15/08/2007||P||Martin May||73 – 77||Steve Baines||Ricky Tomlinson||Susie Dent||118|
|6932||17/10/2018||P||Paul Hollidge||52 – 96||Martin May||Clive Anderson||Susie Dent||135|
|6933||18/10/2018||P||Martin May||117 – 52||Chris Stableford||Gloria Hunniford||Susie Dent||124|
|6934||19/10/2018||P||Martin May||103 – 54||Seamus Bradley||Gloria Hunniford||Susie Dent||134|
|6935||22/10/2018||P||Martin May||108 – 59||Leanne Heath||Gloria Hunniford||Susie Dent||145|
|6936||23/10/2018||P||Martin May||101 – 15||Vicki Griffiths||Gloria Hunniford||Susie Dent||120|
|6937||24/10/2018||P||Martin May||89 – 42||Maria Michaels||Gloria Hunniford||Susie Dent||129|
|6938||25/10/2018||P||Martin May||108 – 67||Alan Tubbert||Paul Zenon||Susie Dent||155|
|6939||26/10/2018||P||Martin May||117 – 49||Dover Dubosarsky||Paul Zenon||Susie Dent||137|