With B, work same as Back until piece measures 14½”, ending with a WS row. Knit 25 sts, join another ball of yarn and bind off center 18 sts. Working both sides at once, dec 1 st each neck edge every other row 4 times - 21 sts each side. Work even until piece measures same as Back. Bind off.
I've just finished the dividing row
, which is a knit row. So do I start the decreases on the very next purl row, and then every following purl row??? Or do I purl the next row as normal AND THEN dec on the knit row (and the next four knit rows)???