[O.B.Left]

Gmb.

I totally agree with Buckets assessment. Totally.

Are you a hitter by chance? Do you dabble in the art of Active Thrust? Just checking. Here is what Im thinking too:

-a little tiny bit outside going back, probably 'cuzz the right arm isnt folding at first. An angled hinge in start up which is good if you're a hitter type. Im wondering if this is all due to an old habit of pushing the club away with the left side? Its indicated given these symptoms, just checking. If so research the RFFT. Also you right arm may be stiff or fully extended at Address. A RFFT blockage. The Right Arm Fans and Bends.
-some left wrist rolling to the inside. Leading me to think that your mental picture is maybe left side centric. See 6-B-3-0-1 first paragraph. Read and re read. If you are a hitter, or a swinger even it will do much to simplify your perception of the backswing by making it a right sided thing. (Without the left sided, standard wrist action stuff that is oh so 2008.) The problem with non aligned rolling is that it can go anywhere but most likely inside which will disturb the plane of the clubshaft and the plane of the left wrist cock (too much around and under with a flattening out of the hand and not enough UP in the left hand, hammering)
-as Buck says a literally flat left wrist instead of a geometrically flat wrist to Top. Practice the Hammer, vertical left hand cocking via a bending right elbow.
-an immediate move to a slightly steeper plane in startdown. Probably due to a premature firing of #1. An early Release. Hit the search function for "startdown waggles" as a cure. This is a must for a pull. Two for every pull on the range as punishment. Do them quickly and then hit a shot without pausing to think and watch it go straight! No guff this is the cure to a pull. It is all about the sequence of accelerating components. You have to save the firing of #1 for Release, dont fire it off in Startdown. "Endless belt". "Punch Elbow". "Hip Slide", "Delayed Turn".
-right wrist flattening out early. Its extremely bent at Top then flat at Impact. Homer wanted us to extend our right arms but with the right wrist frozen in its Impact Fix degree of bend until both arms straight. "Golfs unique move".
-a little vertical hinging through the ball. Perhaps some "steering" an attempt to ward off the clubface closing or the left hand bending. Trade the bending left , flattening right for a bent right , flat left but ROLLING.
-left arm could maybe use some "Extensor Action" so it doesnt go limp too early.

Hope I didnt add to the confusion or make it sound overly critical. I like your action it looks very strong and athletic. I love the way you stop at Top. If you arent hitting you're a strong candidate Id say. If not then I'd still add some right side awareness. Its the old left side centric stuff that gave me a lot of those particular problems anyways. Thats where Im coming from, literally.

Regards
Ob