Here is what I found for the explanation of ESPN's Scouts Inc. basketball grading scale (different from what you found and not as optomistic an outlook for our spring freshman):
http://sports.espn.go.com/ncaa/recruiting/basketball/mens/news/story?id=2639514
The grading scale for basketball recruiting is similar to the grading scale used for football, with a few subtle differences.
Scouts Inc. High School Basketball Grading System
98-100: High-major plus prospect
Player demonstrates rare abilities. He should have an immediate impact at a national program with the potential for early entry into the NBA.
94-97: High-major prospect
Player has the potential to significantly contribute as a freshman for most national programs. He could be a three- or four-year starter and have an opportunity for all-league honors.
90-93: High-major minus prospect
Player has the potential to significantly contribute to a national program as a freshman. He could be a four-year contributor with an opportunity to start over the course of his career.
87-89: Mid-major plus prospect
Player could contribute for three or four years at a high-major program or have a significant impact as a freshman at a mid-major program.
83-86: Mid-major prospect
Player should be a solid contributor and two- or three-year starter at a mid-major program.
80-82: Mid-major minus prospect
Player could be a three- or four-year contributor with an opportunity to eventually start at a mid-major program.
77-79: Low-major plus prospect
Player could contribute at a mid-major school but should be a significant contributor as a freshman at a low-major program.
73-76: Low-major prospect
Player should be a solid contributor and two- or three-year starter at a low-major program.
70-72: Low-major minus prospect
Player could be a three- or four-year contributor with an opportunity to eventually start at a low-major program.
40: Pending Prospect
Player evaluation is pending film.
