These are based on Composite rankings...
2014: 2 top 300 HS decommitments
2015: 3 top 300 HS decommitments
2016: 6 top 300 HS decommitments (2 eventually returned to class & signed with UM) **Transition class from Golden to Richt
2017: 3 top 300 HS decommitments (1 eventually returned to class & signed with UM)
That is an average of losing 2.75 top 300 HS commits when you don't include the recruits that eventually re-committed.
The issue is Miami currently has 9 prospects ranked inside the top 300 HS in March while still in the mix for other top 300 recruit. That total of 9 currently equals the number UF signed in 2017. It was 6 HS prospects inside the top 300 for UF in 2016. Then 4 HS prospects in the top 300 for UF in 2015.
Miami likely loses some of those top 300 commits because that's the nature of recruiting. They probably offset some of the losses with additions later like legacy Al Blades, a top 300 recruit. It would take a monumental collapse though for UM to lose 6-7 of those top 300 prospects by NSD. Possible, but not something I would guarantee happening considering the recent average has been 2.75 top 300 decommitments per year.