The Apterous Masters, formerly known as the Countdown Online Masters, (or by its acronym COMA), is a tournament organised each February/March, and is a straight knock-out event between 8-32 players. Traditionally organised by Ben Wilson, it was guest-hosted by Zarte Siempre in 2015, and he then assumed its organisational duties in 2017.
Top players are seeded into the first-round draw after being judged on their skill at the game as displayed in both televised and off-screen performances, such as at COLIN or CoBris events, or in online competitions such as COOT or COGST. Apterous ratings are also used as a judge of skill.
Players who decline their invitations will be invited again the following year, but will not be invited a third time if they decline two invitations in a row.
The 2010 tournament, the first held under the new name of Apterous Masters was announced at the beginning of February of the same year. The first qualifying round began on 14 February, and the tournament ended with Kirk Bevins beating Jon O'Neill 6-3 in the Grand Final on 13 April 2010.
The 2011 tournament began on 20 February with the first qualifying round. In total, 63 people took part, a record for the tournament. Innis Carson beat Edward McCullagh 6-1 in the Grand Final on 8 April 2011.
The 2012 tournament ran from late February to early April. In total, 42 people took part (17 invited Masters and 25 qualifying entrants). Bob De Caux was one of those who had to qualify for the tournament. He won matches against several tough opponents before beating Adam Gillard 6-4 in the Grand Final on 11 April 2012.