Joanna kindly pointed me in the direction of official Lucky errata. I’m going to share my fix with you anyway! My method is worthwhile because it also accounts for the possibility of off-gauge knitting.

First, let’s examine the problem. After some 7? of knitting on the front, you start the sweeping decrease that makes the neckline. After another 4? of knitting, you bind off for the armhole and start making raglan decreases. This leaves you an “error zone” where you can incur misalignment that will be indetectable until you knit the final rows of the sweater’s front.

To account for this, I used some really simple math. This method is applicable to any size, any gauge.

Start the neck decreases. On most sizes there is a decrease every row at the neck edge for most of the sweater. At some point the pattern changes to a decrease every other row. Ignore the change. Just decrease every row until after the armhole bind-offs.

After you’ve bound off the armhole, finish the row, and work another row to bring you back to the side edge of the sweater front.

 

• Now count the number of stitches left in the row and write it down.
• Looking at the pattern, figure out how many stitches you’ll decrease to make the raglan sleeve shaping. (For size S, the number is 20.) Jot this down, also.
• Figure out the number of rows required to make the raglan shaping, using information in the pattern. For size S, this number is 54.

 

Now, solve this equation: (Number of sts in row) – 3sts for selvage purposes – (number of sts decreased for raglan shaping, not counting bind off) = total number of decreases needed at neck edge.

Using that answer, solve this equation: [(total number of neck edge decreases needed) – (1/2 of # of raglan ROWS) ] x 2 = number of rows in which you decrease EVERY ROW at the neck edge.

When you’ve completed that number of rows, switch to decreasing on every other row. You’ll end up with three stitches at the end of the raglan shaping, which leaves enough selvedge for the sweater to be sewn together neatly. Yay!

If you’re knitting a Size L, there is some chance that you’ll get a negative answer to the second equation. If this happens, switch immediately to neck edge decreases every other row. When you have completed all necessary neck edge decreases (the number you calculated in the first equation), stop decreasing at the neck edge. Continue the raglan shaping as written, and you’ll end with 3 stitches.