Partido alto — the sixteenth-note samba rhythm the tamborim, the pandeiro and the rhythm guitar share, and the backbone of pagode. Over one cut-time bar (sixteen sixteenths) the strums fall on "x . x x . x . x | . x . x x . x ." — a front half that starts on the beat and a back half that starts off it, each half an answer to the other. Downstrokes on the eighth-note grid, upstrokes between.
The feel: like the bossa clave, it is a two-sided pattern; played the other way round (back half first) it is the same groove in the other direction. The surdo bass under it is plain half notes with the weight on 2, and the piano only pokes at the off-beat sixteenths so the guitar stays in charge.
Listen for the strum that lands on beat 2 in the second half of the bar (the "3.0" here): everything around it is off the beat, so that one on-beat stroke is the anchor.
Practice: mute the strings and play the whole sixteenth grid down-up-down-up, then let only the pattern's strokes ring. Authored from standard practice — no transcribed source in the workspace.