A simple idea to motivate students year long:

One simple idea that came to me to help students motivate for the whole year. Tell students they start the year with an A. Structure the class so that all students will be able to send home an A in math for the first progress report. Then communicate the expectation that things will get harder and students are capable of keeping that A grade. Parents and peers might put a bit of pressure that could help motivate students to work hard to preserve that grade.

I would like some feedback and possible drawbacks on this idea?