Selvedge edge to cast off edge mattress stitch

If any such thing exists, I’m sure someone on this forum will know it. Is there a formula for working out how often to miss a row to ensure even distrbution? I need to matress stitch the cast off edge of a front piece to the selvedge edge of a cuff to cuff knitted sleeves and yolk. I’ve got 102 stitches to tie up with 155 rows between the markers. Thanks in antiipation.

It’s really working out a ratio given the number of stitches and rows that you have. For 102sts to 155 rows you’ll be stitching 2sts for every 3 rows. You would attach a stitch to a row, attach the next stitch to the next row then skip a row.
It’s like the video here from Suzanne Bryan (see especially 20min):

Thank you so much. So its 155 rows divided by 102 stitches which equals 1.5 rows per 1 stitch which in ‘whole’ rows is 3 rows to 2 stitches. Brilliant!