Using SAMAccountName to Login to ADFS in Windows Server 2012R2/2016

When setting up Active Directory Federation Services (ADFS), by default it requires that users log in using their User Principal Name (UPN) or using DOMAIN\username. However this can be confusing to users, especially when you're in a single domain environment.

It took me way longer than it should have to figure out how to accomplish this. Hopefully this will help some folks find some more recent info than all the ADFS 2.0 stuff