Is that lace row correct?

I was working on a project and came to a row of knitting that made me pause while I figured out what it meant. Here's what I read:

(k2tog) twice, (yo, k1) 3 times, yo, (ssk) twice

My first instinct was to add in that yo before the ssk twice (so it would be yo, ssk, yo , ssk), but fortunately I stopped myself quickly to take a second look at the instructions. 

If I compared the (k2tog) twice format with the (ssk) twice format, I could see that it really just meant to repeat the ssk twice and not the yo, ssk twice. (I think the parentheses around k2tog and then ssk were intended to make it clear that those were the only stitches to be repeated, but since it was just one instruction in the parentheses it was a bit confusing at first glance.)

But if I still wasn't sure which part should be repeated, there's one more way I can double check, and that's the trick I wanted to share with you today.

Most of the time when you are working a lace pattern, the number of stitches within the lace portion  is going to stay the same. (The exception is if there are increases on the edges or center of a shawl, but then it's just those edge stitches and not the actual pattern stitches. There are times when stitch counts will change from row to row, but if that happens, the designer should give you a stitch count at the end of the row so you can see that the counts are changing.)

So if the number of stitches stays the same, that means for every increase there needs to be a corresponding decrease (and vice versa). So if you have a yarn over (which adds one stitch), you need to decrease (which subtracts one stitch).

Much of the time, the increase and decrease will be paired (meaning they happen one after the other), but sometimes  (like in the pattern I was working) they are not. It was wanting to have that increase and decrease right next to each other that caused my first instinct to add in the yarn over before the second ssk rather than having two decreases in a row. But if I did that, I'd be adding one extra stitch on that row that shouldn't be there.

Let's take a closer look:

First, we k2tog twice. That's two decreases so we have subtracted two stitches.

Then we have  a (yo, k1) repeated three times. That is 3 increases. So we had subtracted two but now we've added three, so we now have one additional stitch.

Next comes another yarn over. That's another additional stitch so we now have two additional stitches.

Finally we have ssk twice. Two decreases means subtracting two stitches. That cancels out the two additional stitches above so we are back to zero.

If I had done ssk, yo, ssk, then there would have been one extra stitch.

Let me show you that another way:

The image shows the line of instructions written out fully. The top example is the correct one. You can see each decrease is paired with an increase. In the bottom one, there is an additional increase that does not have a paired decrease. Therefore, the first option (the one with the checkmark) is the correct way to read this line of knitting.

So if you ever wonder if you're reading a lace row correctly, just write it out and match up the increases and decreases to figure it out. (Again, some lace patterns will change stitch numbers on rows, but a good pattern will give you the stitch count at the end of the row so you'll know that's happening.)