There are a number of people running ‘Start When Full’ tournaments these days(including me) and because they ‘start when full’ the minimum number of participants is often equal to the maximum number of participants. When this is done you get something like:
ie. The minimum & maximum are set to 10 players but for anyone thinking about joining it displays as ‘Players 10+’. The ‘+’ sign leads to uncertainty about what people are signing up for and when exactly it will start, possibly discouraging participation.