NCU Challenge Cup

The NCU Challenge Cup, also called the NCU Senior Challenge Cup and the NCU Senior Cup, is the most important provincial cricket knock-out cup of the NCU jurisdiction in Ireland. The competition began in 1887, with eleven clubs participating in the first competition, North Down eventually beating North of Ireland in the final at Ormeau.
The Cup is open to teams playing in the Premier League and Section 1 of the NCU Senior League. It is sponsored by Arthur J Gallagher and marketed as the Arthur J Gallagher Challenge Cup.
Matches consist of one innings per side, with fifty overs bowled per innings. Where matches are interrupted or delayed because of weather, the number of overs may be reduced to a minimum of 20. Duckworth Lewis is employed where a match is interrupted after it has started.
The most successful club in the competition is North Down with 32 victories (1 shared)
CIYMS are the current holders after beating Instonians by 98 runs in the 2019 final.
List of finals.
Source for finals up to 2002: J. Clarence Hiles (2003), "A History of Senior Cricket in Ulster". Comber: Hilltop Publications Ltd.
References.
CricketEurope archives