Standard rib patterns create vertical stripes by alternating a given number of knit stitches with a given number of purl stitches. But who says all ribs have to be the same? Mistake stitch ribbing, which you see in the following figure, is a 2 x 2 rib worked over 1 fewer stitch than required to make it even.
To create mistake stitch ribbing:
Cast on a multiple of 4 sts, plus 3 sts.
Work every row: * K2, p2; rep from * to last 3 sts, k2, p1.
Rep for pattern.
