Before I begin, a little background is necessary. I have to confess, my stitches run to the tight side, and this accounts for most of the problems I encounter in increases and decreases of certain types. As I've gotten more comfortable with the craft I have managed to get to the point where a k2tog (usually) does not involve the use of KY Jelly and a ball peen hammer, but for some reason I still sometimes have a hideous problem getting the RH needle through the back loop when working an M1 increase. I was especially flummoxed by this because I didn't have nearly the same kind of difficulty with the back loop when doing a kfb increase and that's knitting the back of the same [expletive] stitch! You'd intuitively think that that would be tighter, and therefore harder. (Okay I would think that anyway.)
But after extensive study I developed both a theory as to why one is harder than the other and a couple of methods for working around it. So as a public service, I submit this thread to share my experience strength and hope with the newbie who still suffers.
First the theory. When knitting the front and back, you're only working on one stitch, but when you pick up a strand between stitches, you naturally pull the stitches on either side of it tighter. And because you're picking up the strand from the row below the one you're currently working on, the "legs" of the loop are at a shallower angle, so geometry is conspiring to make the opening you're trying to exploit smaller than it would if you were working on a stitch in the current row. And if you naturally knit tight anyway, this compounds the problem.
But there is hope! :cheering:
Last night as I was working on a particularly stubborn WIP, I discovered that if you lift the strand from below with the RIGHT needle from the back side, it is sometimes possible to jam the LEFT needle under it through the FRONT loop which accomplishes the same thing. If that doesn't work, you may be able to insert the RH needle through the front loop PURLWISE (i.e. from right to left through the FRONT loop) and then rotate it to the back side (kind of like twiddling ones thumbs...er... needles). this gets the RH needle into the right position. Which is, after all, the goal -- orthodoxy be damned.
It's also helpful if you hold both needles as close to horizontal as possible because this decreases the tension on the loop you're attacking and makes ANY technique you use easier. In fact, this subtle change in position may very well obviate the need for any unorthodox mechanics (like those above) in the first place.
The purists and knitting police of the world at large will probably disdain such things, but I'm too pragmatic to care. If it works, that's what you do. Fortunately, the knitting police don't hang out on KH (and a good thing too!).
Hopefully this epiphany will help someone. If it's unclear, then please don't hesitate to call!