sentences:  He was awarded a rating of 135 by Timeform.In their book "A Century of Champions", John Randall and Tony Morris rated Sir Ivor as a "superior" Derby winner and the seventh best Irish racehorse of the 20th century.Vincent O'Brien rated Nijinsky and Sir Ivor as the two best horses he had trained, placing Nijinsky first for brilliance and Sir Ivor first for toughness.