15 round format (old)

Ben Wilson was the first series champion under the original 15-round format.

The 15 round format is the arrangement of letters, numbers and conundrum rounds used from Series 46 until 22 March 2013. Whereas the 9 round format used in previous series (and equally the 14 round format used in past series finals) gave contestants their choice of selections in an equal number of letters and numbers rounds, the 15-round format saw the contestant in the champion's chair pick an extra letters selection but only one of the three numbers selections. This offered an advantage to the contestant in the challenger's chair in close games, as they had the choice of selection in the final numbers round.

For games where there is no reigning champion (finals games and those which follow the departure of an octochamp), order of play is decided by an off-screen coin toss. The champion picks in odd-numbered rounds, and the challenger in even-numbered rounds. Alongside the short intermissions for commercial breaks before Rounds 6 and 11, book-ends by Teatime Teasers and the celebrity guest provide an anecdote after Round 5. Furthermore and since September 2007, Susie Dent presented the Origins of Words slot after Round 9.

In 2013, it was announced that the previous arrangement of letters and numbers was to be changed to a new 15-round format of LLNLLNLLNLLLLNC in accordance with Channel 4's shuffling the lengths of the show's three halves. The change took effect on 25 March 2013, in the midst of Series 68.

Rounds

Rnd	Selection	Champion (C1)	Score	Challenger (C2)	Others	Max.
1	C1LETTERS		–
2	C2LETTERS		–
3	C1LETTERS		–
4	C2LETTERS		–
5	C 1 N U M S →		–
TTT	TEATIME TEASER
6	C2LETTERS		–
7	C1LETTERS		–
8	C2LETTERS		–
9	C1LETTERS		–
10	C 2 N U M S →		–
TTT	TEATIME TEASER
11	C1LETTERS		–
12	C2LETTERS		–
13	C1LETTERS		–
14	C 2 N U M S →		–
15	CONUNDRUM		–

	Chosen by champion	Chosen by challenger	Total
Letters rounds	6	5	11
Numbers rounds	1	2	3
Conundrums			1