A simple thing that works shockingly well for creating a functional bossa groove that breathes. You’ll recall that this “subtractive method” is a way of revoicing the rhythms in Syncopation, based on how they line up with an underlying eight note, two drum pattern. It’s not that hard.
The pattern on this system is BSSB-BSSB— hopefully you can clearly see the bossa bass drum rhythm contained in that?
On a bossa, the groove is supposed to vary with the music, similar to what happens with the snare drum in jazz, and this system accomplishes that really well, with some useful bass drum variations, and snare drum variations. When people play this style they tend to get too locked into the repeating bass drum rhythm especially. Here you’ll often be sketching it out, suggesting a samba at times, with the bass drum weighted on beat 3, or a baiao feel, with the bass drum on the & of 2.
Learn the concept, play through the examples, then practice it reading out of Syncopation— pp. 6-7, 9-10, and 30-45. On the full page exercises, it would probably be best to isolate some repeating two measure phrases, and read the pages straight through later.
An enterprising student could extend this with the following patterns:
SSSB-BSSS
BSSB-SSSS
BSSB-SBSS
The BSSB-SBBS pattern is also good, but that seems a level harder. Here’s a moderate-tempo loop for you to drill it with, and a brighter tempo loop, and a samba— you may want/need to alter the cymbal rhythm on that one.