We use recovery strokes all the time to ensure that we are using the most effective part of the bow with the right bow speed and bow division.
The example here is ‘Allemande’ from Bach’s Partita No.2 in D minor, bars 4-5.
We need to plan our bow division so that when playing 3 notes slurred and 5 notes separate (or indeed any similar uneven patterns that Bach often used) we do not just creep higher and higher in the bow.
Here the slurs work well starting at the balance point of the bow. To get back to the balance point for the next slur, we need to make our up bows gradually longer than our down bows. The last up bow before the slur is the longest and strongest as the phrase is building towards the next slur or high point of the phrase.
Bach used slurs not only as an articulation marking but as an indication of musical line, as the beginning of the slur is often the high point of a phrase. The slur begins strongly and has an implied diminuendo and the separate notes that follow the slur crescendo again towards the beginning of the next slur.
For instance in Bach’s ‘Allemande’ the slurs in bar 12 (3rd beat onwards) and bar 13 (1st and 3rd beats) are on the strong beats, and the détaché notes that follow them start softer and then crescendo towards the next slur or strong beat.