A sampling of short scenarios showing the algorithm at work.
The algorithm tries to match you to your #1 ranked program first, so if you rank a program that is not your first choice in that spot there is a chance you will match to that program without ever knowing whether you could have matched to your real first choice. Remember, it is impossible to know how a program will rank you so there is no point letting that influence your ranking decisions.
No. In this case, both program and applicant choice dictate that Applicant A would match to Program 1 before Applicant B.
No. The algorithm may make a tentative match between Applicant B and the program during the running of the match, but the result would not be finalized until the algorithm determined Applicant A’s match result. If none of the programs Applicant A ranked above Program X were available, Applicant A would be matched to Program X.
Yes. The algorithm will first attempt to match the applicant into Programs X and Y first, but if those are not possible it will move on to Program Z. Because the applicant is ranked first by Program Z, the applicant will match there.
The algorithm will first attempt to match you to the programs you ranked #1 through to #6, but if those are not possible it will move on to your #7 rank. And if you’re ranked #1 by the program, you’ll match there.
During the match process, the algorithm may establish a tentative match for the other applicant before it determines your result, but if your best match result is this program you will match there and, assuming the program has no remaining positions, the algorithm will move on to the next rank on the other applicant’s ROL.
The algorithm looks at applicant ROLs first. So it always tries to place an applicant into their #1 ranked program before moving on to their #2 ranked program.
But ranking a program higher on your ROL does not necessarily mean you have priority over another applicant who may have ranked it lower. The algorithm also considers where applicants are ranked on Program ROLs.
There are three reasons an applicant might not match:
- The applicant was not ranked by a program they ranked
- The applicant did not rank a program that ranked them
- The applicant was ranked by a program they ranked, but the program filled with more preferred applicants
Note for couples: if an applicant participated in the match as part of a couple, their match results are linked to their partner’s results. If one partner does not match to any of their paired ranks, both partners could go unmatched. Our couples FAQs explain more.
If a program goes unfilled, it is because all of the applicants on the program’s rank order list either matched to a more preferred program or did not rank the program.
The algorithm ensures that applicants match to the highest ranked program that also ranked them within the number of available positions. If you went unmatched, but a program you listed on your rank order list has unfilled positions at the end of the match, it means the program in question did not rank you.
If an applicant ranked #1 by your program went unmatched, it means the applicant did not rank your program.