OpenCV-Python selecting the Accuracy of ROI

Hello everyone hope you are doing great…
Am wondering how can someone select the ROI accurately like in the example below taken from ROI

>>> import numpy as np
>>> import cv2 as cv

>>> img = cv.imread('messi5.jpg')
>>> ball = img[280:340, 330:390]
>>> img[273:333, 100:160] = ball
>>> cv.imshow('image', img)

for the ball to look like that is there a strategy or technique?

i read this 3 times, but i still don’t know, what you want.

can you try to explain better ? what are you trying to achieve ?

How can you extract some coordinates of some region on an image in this case the coordinates of the ball.?

there is no “strategy” or “technique” here.
both regions were choosen manually
(the dst region was probably moed up a bit to match part of the white line it copied)

Alright thanks very much, sir