SSK: the left-leaning decrease

SSK (slip, slip, knit) is a single decrease that turns two stitches into one with a left-leaning slant. You slip two stitches knitwise, one at a time, then knit them together through the back loops. It's the mirror of k2tog (which leans right), and the two are paired constantly in patterns: sock toes, raglans, hat crowns and lace.

How to work an ssk

1. With the yarn in back, insert the right needle into the next stitch as if to knit and slip it to the right needle without knitting it.
2. Slip the next stitch the same way: knitwise, one at a time, never both together.
3. Insert the left needle tip into the fronts of both slipped stitches, so the right needle sits through their back loops.
4. Knit both together through the back loops and let them drop off.

One new stitch, leaning left. One stitch decreased.

Why knitwise? Slipping knitwise turns each stitch around so it lies flat and untwisted after the decrease. Slip them purlwise and you get a twisted, bumpy decrease, the single most common ssk mistake.

When to use ssk (and when k2tog)

The convention in most patterns: ssk at the start of a shaped section or after a marker, k2tog at the end or before it, so the decreases lean into the shaping and mirror each other. On a sock toe or raglan seam, that symmetry is what makes the line of decreases look deliberate and clean.

Common mistakes

• Slipping purlwise: produces a twisted decrease. Both slips are knitwise.
• Stretching the stitches while slipping: work at the needle tips to keep the loops small; a stretched ssk looks sloppy next to a neat k2tog.
• A loose ssk next to a firm k2tog: ssk tends to knit up slightly looser; keep the tension snug. Some knitters use an "improved ssk" (first stitch knitwise, second purlwise) for a flatter result, worth trying if yours look untidy.