The seventeen stroke roll is eight double strokes that release into an accented single. It is the longest of the standard stroke rolls, filling two full beats.
Sticking
R R L L R R L L R R L L R R L L R
Capital letters are main notes. Small letters are grace notes played just before the main note.
How to practice it
Play it at a slow tempo with the click, counting out loud.
Listen for evenness: every double should have two equal notes.
Raise the tempo 5 BPM at a time. When it gets messy, drop back 10.
Practice it with a click and count out loud. Two beats of doubles, then land the release on beat 3.
Where you will use it
It is a common two-beat roll in marches and concert snare music.