Monica Knits

The two socks differ in the number of loops of each stitch within the chain stitch selvedge that were picked up from the side of the heel flap. On the left, both loops of each chain stitch were picked up. On the right, just the back loops. The arrow points to the center of a column of knit stitches. On the left, you see the last column is complete. On the right, by picking up just the back loops, a ridge (1/2 a knit stitch) is formed.

In a plain sock, I prefer the ridge, particular for a man's sock as it gives a crisp edge.

Related Posts:
Basic Turning Heel (2 loops picked up for gusset)
Ridgeline Turning Heel . (back loop only picked up)
Picking Up Gusset Stitches.