from 1954

The format for the championships has changed many times throughout its history. In the early years of the championships, men competed in four different categories: Doubles, 4-man team, 8-man team and masters. Up until 1963 women did not participate in the event. The first year that women did take part, they competed in 4 different categories, doubles, four-person team (European Style), four-person team (American Style) and masters. This is the only time the "European Style" has been used in the championships. In the following championships the European style four-person team was replaced with the five-person team event (American Style) and was used until 1979.

Current format and disciplines

Singles, Doubles, Trios, Team of Five, All Events, and Masters have been the disciplines for both genders since 1979, with 6 women and 6 men on each team. The medalists for these events except the Masters from 1979 to 2007 were determined by total pinfall.

After the conclusion of singles, doubles, trios, and five-person team events, the All Events medals are presented to the top three bowlers of both genders who have accumulated the most pinfall over the 24 games.^[2]

Addition of Match-Play in the finals

Beginning in 2008, a medal round was introduced for singles, doubles, trios, and 5 five person team event. The Medal round consisted of the top four qualifiers playing a knockout format to determine the medalists (1 vs 4 and 2 vs 3, winners of those matches face each other in the final).

The masters event has only recently changed with the onset of the championships splitting into 2 different events. Up until 2005 the top 16 would bowl a 16-game Round Robin with the top 3 bowlers after the 16 games advancing through to a stepladder final. From 2005 to 2011, the masters was played using the matchplay style, best of 5 format.

From 2013-2015, the top 24 men and women in All-Events advanced to the Masters event. All players will bowl six games with the All-Events total carried forward. The top 8 after 30 games advance to seven games of round robin match play, where 20 bonus points are awarded for a won match and 10 bonus points for a tied match. The top 4 advance to the semifinals, which is a one-game match, 1 vs 4 and 2 vs 3. The semifinal losers will earn a bronze medal. The semifinal winners advance to a one-game final match to determine gold and silver medals. In 2017, the masters format (still consisting of top 24 men and women) reverted to matchplay style, best of 3.

Modification in Team Event

Beginning in 2017, the five-person team event was modified. Qualifying was still all five players bowl ten frames each with their scores added together to determine the overall score. In the medal round, the five players bowl a best of 3 baker format, where players bowl in order one frame each (frames 1-5) and repeat the order from frames 6-10.