All wrist casting is not 10-2 and not all casting from 10-2 is with the wrist. However, most people who think of 10-2 in their head cast with their wrist and the rod tip travels in a convex arc resulting in a wide or no loop. The reel remains fixed and the tip moves like a windshield wiper. Just as important as where the rod stops is the direction it took to get there. We could both stop the rod at the exact same point on a clock face, say 2 o'clock, and get very different results. For example,
in drawing A, the rod tip moves from 10-2 in a straight line and forms a tight loop. In B, the rod tip stops in the same position in the front and back cast but the tip is travelling around in a circle to get there and the reel is barely moving. The tip of the rod is also travelling slightly down at the stop after having gone around in an arc resulting the the line travelling down as well and a very poor or no loop.
Drawing C is for a short cast and shows 11-1, which is NOT 10-2. Drawing D shows the path for a lot of fishing casts, slightly up on the back and slightly down on the front so that the loop unrolls a couple feet above the surface not 8-10 ft above the surface as it would in drawing A. Drawing E is a 10-2 proper cast for a longer length of line and does not fit on the same clock as the cast in drawing A. Casts of a different lengths could still be from 10-2 but would require different sized clocks as the length of the stroke would be longer or shorter. The longer stoke in E does not fit inside A so how is a student to know what size clock to use. Using a clock does not help the student visualize a straight line path of the rod tip which the half to have to make a tight loop. One can make a stop at 10 and a stop at 2 10 different times and get 10 different sized loops.