- 1 and 2 — the two ends of one popping crease
- 3 and 4 — the two ends of the other popping crease
So 1→2 is the 3.66 m across the pitch and 2→3 is the 17.68 m down it. On a side-on camera that means two short strokes at the left and right of the picture, not a box around the whole strip. Which end the bowling comes from is worked out per delivery, so it does not matter which crease you start with.
These look like the long edges, not the creases.
1→2 spans px and 2→3 only
px. A pitch is five times longer than it is wide, so measured this way every ball would come out short and wide of the stumps.
Scrub the video to the first ball of the match and put its timestamp above. Every other delivery
is found from it, because the scorecard already knows how long after it each one was bowled.
The feed timestamps that ball at 10:00:51.
Nothing is measured yet. The next step offers 20 deliveries to check these creases against, and processing the whole match is one click past it.
The 1 measurements already taken stay until a run replaces them, but they were measured with whatever calibration was saved at the time.