In the 2019 cycle, they selected 60 4yr. The rest were ranked on a waitlist to receive the 3yr, which they gave around 20. Only applicants applying for the 4yr can be issued the 3yr, and to be more accurate it's actually a 3.5yr scholarship because they actually do cover tuition for the first year and the stipend begins paying you in October (which is the start of the fiscal year for the gov't). So it's equivalent to a 4yr HPSP with the only difference is you don't get the monthly stipend for the first few months of school. But you will still owe back 3.5 or 4 years of service - I never got a clear answer on this one since I didn't get to read the contract myself.
I ended up as #1 or #2 left on the waitlist in case anyone else changed their mind, but got the call in October after starting D1 year that everyone else commissioned and the Navy was closed, unless I wanted to accept the HSCP which was still open to me, but I wasn't going to take that deal attending MWU. I was already talking to the AF recruiter by that time preparing to reapply for the AF 3yr, and glad I trusted myself and took that route instead.