Mark Hope
Adventurer
In my D&D games, players don't know their stats (abilities, saves, hit points, skill ranks etc) but they still roll their own dice. I add the relevant mods as needed. Helps immersion, keeps them guessing, yet still allows them to retain ownership and that vital sense of control and involvement in the action. I've run games this way for close to 20 years - works nicely - but I do think that players should roll their own dice (where appropriate), as that's part of the fun for many players.