It’s called a centered double decrease because it doesn’t really lean to the left or the right. Instead, the slipped stitches recede and the center stitch becomes prominent. To begin a S2KP, work to where the decrease needs to be and slip two stitches as if to knit, slipping them at the same time. This is the same sort of move you make to begin a knit two together. As you can see, this decrease makes the slipped stitches recede into the background while the knit stitch pops out, making a centered double decrease that’s great in lace knitting and other times you might need to take out more than one stitch at once.
