Grand slam winner
A grand slam winner is a contestant who becomes an octochamp (or viscount in case of Series 46), series champion and champion of champions, essentially giving them an unbeaten run of 13 to 15 wins (depending on the length of their Championship of Champions). This is regarded as the highest accolade to achieve on Countdown.
Grand slam winners are typically undefeated in all of their televised competitive games alone, excluding games in the Supreme Championship, the 30th Birthday Championship and special episodes (unless they had a previous stint as a contestant in an earlier series, in which they lost a game). As a point of interest, each of these contestants' defeats (if any) are listed here.
To date, there have been seven grand slam winners:
- Harvey Freeman won Episodes 459 through 466, the Series 10 finals and Championship of Champions III. He also won the Supreme Championship. His only loss as a solo player on Countdown was to Mark Nyman in Episode M45; as well as a special episode where his team, captained by Gyles Brandreth, lost to a team captained by Bill Tidy.
- Nic Brown won Episodes 658 through 665, the Series 14 finals and Championship of Champions IV. He did not return for the Supreme Championship nor participate in any special episodes, and thus remains undefeated.
- Don Reid won Episodes 1361 through 1368, the Series 25 finals and Championship of Champions VII. His unbeaten record was ended in the Supreme Championship by John Clarke.
- Scott Mearns won Episodes 2553 through 2560, the Series 41 finals and Championship of Champions X (a shorter-than-normal CoC in which he received a bye to the semi-finals). His unbeaten record came to end in a special episode against Natascha Kearsey.
- Graham Nash won Episodes 2813 through 2820, the Series 43 finals and Championship of Champions XI. He also won a special episode. He did not return for the 30th Birthday Championship, and thus remains undefeated.
- Zarte Siempre won Episodes 6774 through 6781, the Series 78 finals and Championship of Champions XV. He previously won five heats in Series 69 before losing his sixth, and has more wins than any other grand slam winner (20).
- Ahmed Mohamed won Episodes 7605 through 7612, the Series 84 finals and Championship of Champions XVI. He remains undefeated.
All but one of these were No. 1 seed for their finals; the only exception is Graham Nash, who was No. 2 seed behind David Williams.
Grand slam points totals
Typically, a 9-round grand slam winner played 12 9-round games and 2 14-round games. As Scott Mearns only played two matches in his Championship of Champions, his 872 score comes from just 13 games. Mearns's average 9-round score is 64.45, and thus his theoretical score for 14 games would be 936. Thus, he is listed above Don Reid here.
Graham Nash is the only grand slam winner who played his original series in the 9-round era and the Championship of Champions XI in the (old) 15-round era. He score 684 points in his Xicount run, and 406 points from 4 games in the COC. Therefore, his points total if reducing his score by 9/15 accordingly for the CP, CQF, and CSF games, and by 14/15 for the CGF game, becomes 270 for this run, and 954 points from 15 games if he is to be included in 9-rounders. However, as he played an additional game in his COC compared to Freeman, Reid, and Brown; and two more than Mearns, this cannot be considered to be a comparable total to Freeman or Mearns's scores. If his three COC games (excluding the final) are thus reduced to two, his total becomes 888.
Doing the calculations in reverse, i.e. multiplying his Series 43 games by 15/9 (and the final by 15/14), is 991.666666 for the first 10, 95.357 for the GF. Thus this gives him 1087 for his Xicount total and 1493 for his 15-game total.
(adjusted for 9-rounders, 15 wins)
(adjusted for 9-rounders, adjusted for 14 wins)
(adjusted for 15-rounders, 15 wins)
There have only been two grand slam winners exclusively in the 15-round era, and both of these runs came after the change to the new 15-round format in 2013, and both had COC runs comprising of four games.