A tier system is not an idea to shy away from either, in my opinion. WGT took huge advantage of this early on and created a working system. Obviously, I understand that this isn't WGT, but I feel like they, as well as many other online golf games, have a lot to draw from.
For example, each tier should have requirements:
- Rookie - Rounds played: 0. Scoring average: >90.
- Amateur - Rounds played: 250. Scoring average: 76-90.
- Professional - Rounds played: 1,000. Scoring average: 68-76.
- Perfect Golf Professional - Rounds played: 5,000+. Scoring average: <68.
Users could play tournaments based off of their tier. Scoring average is reset upon "tiering" up. Additionally, I think there could be several other requirements for achieving the next tier, such as birdies made, hole-in-ones, match play victories, tournament victories, etc. That way it wouldn't only be about an input of time, but an output of skill.