I count 19 Sufi editions between Sufi 9 and Sufi 27.
Each Sufi uses a set of 50 openings. 50 * 19 = 950.
Where did you take the other 50 openings?
#.
slim drum
slim drum
Actually Sufi 11 was 100 games (50 openings):
https://tcec-chess.com/#div=sf&game=1&season=11
you may check if there are some duplicates in the book you used