Elroy, not that I am defending a CoS which is designed to screw the industry, but the interpretation of:
25.1.3 “You will be rostered free of duty at your Home Base for minimum of 9 designated days off in 6 roster periods and 10 rostered days off in 6 roster periods. The minimum number of days off in a roster period for a pilot will be notified to the pilot no later than before the end of the preceding period.”
Means that in one year (12 roster periods) 6 months will have 9 days of DDO's and the other 6 months will be rostered with 10 DDO's = 94 DDO's per year.
But as you pointed out they can give you those down route.