CDD — Centered double decrease (Abbreviation)

CDD stands for "centered double decrease" — a three-stitches-to-one decrease, like sk2p, but built specifically so the resulting stitch shows the middle of the original three stitches on top, with no directional lean to either side. This centered, symmetrical look is CDD's whole reason for existing over the simpler, more common sk2p.

How to work it

Slip two stitches together, knitwise, as if to knit them together (inserting the needle through both as a unit). Knit the next stitch. Use the left needle to lift the two slipped stitches up and over the just-knit stitch together, and off the needle.

Why this particular sequence centers the result

Because the first two stitches are slipped together (not one at a time) before the third is knit, all three stitches' relative positions stay more balanced through the decrease than sk2p's sequential slip-then-knit-then-pass approach — the middle of the original three stitches ends up sitting visually on top of the finished decrease, rather than one side dominating.

Where the centered look is worth the extra care

CDD is the standard choice at the very spine of many leaf and diamond lace motifs, and at the center point of a triangular shawl worked from the top down, specifically because those design elements read as visually symmetrical only if the decrease itself doesn't lean — a leaning decrease like sk2p at a spine or centerpoint looks subtly lopsided in a way that's genuinely noticeable once you know to look for it.

Related abbreviations

• sk2p — a simpler, left-leaning double decrease, worked with a different sequence
• k2tog / ssk — single decreases, each reducing two stitches to one rather than three to one

FAQ

Is CDD harder to work than sk2p? Slightly — the together-slip step (slipping two stitches at once as if to knit them together) takes a bit more care than sk2p's simpler one-at-a-time sequence, but it's a small learning curve for a genuinely different, more symmetrical visual result.

Does CDD use more yarn than sk2p for the same reduction? No meaningfully different amount — both reduce the same three stitches to one; the difference between them is entirely in the resulting stitch's visual lean, not in yarn consumption.