Does anyone remember the title of the book by an American author
named, Bob Miller where mathematical percentages were taken into
consideration? Characters included: one who weighed less than 100
pounds, a horse with a sense of humor, and another who in real life
had been a personal friend of the author?s who had received much
praise and awards at his Alma Mater?

There's a list of books by Bob Miller here. Maybe one of these titles
will ring a bell:

http://bobmillerwrites.com/bobmiller.htm