1.)
v> v> v> >...
2.)
v> > v> > v> >...
3.)
> > >
Each of these movie files is 15 frames long. Mario is running right, but different directional buttons are pressed.
By observing the value at 0x0400 (X-Subpixel Position address) I can see the following.
Subpixel value-> Frame 0 Frame 15 Frame 20
Movie 1 160 224 96
Movie 2 160 240 112
Movie 3 160 32 160 + 256 (1 pixel)
As you can see, movie 1 and movie 2 managed to cover more distance but somehow lost it by frame 20 to movie 3.
On movie 3, Mario gets ahead one pixel (even though 0x0086 (X-Position) states the same value for all thee movies at frame 20) and the speed address states values on the range of 38 ~ 40 for movie 1 and movie 2 whereas it states only 40 for movie 3.
Either I found a way to temporarily cover slightly more distance or I missed something and movie 1 and movie 2 are both slower, even at frame 15.