Accent the Unexpected
How to play
Strum steady eighth notes on one chord. Accent the backbeats (beats 2 and 4) by strumming them a little harder.
After a minute, move the accents to the off-beats, the "ands" between the beats. Keep the strumming hand moving down and up the whole time.
Then try accenting only one chosen beat in each bar and see how the groove changes.
Challenge
Change the accent pattern every two bars without stopping or losing the beat.
Tips
The strumming hand never stops. Only the strength of each stroke changes.