What are the football betting charts, and what are they used for?

Question

Yesterday my friend asked me about football betting chart, he though I’m a professional gambler but I didn't know what the heck is football betting chart, can someone tell me what is it and why it is used for???

Answer 1

On a paper make 11 lines equal distance on vertical and horizontal. You have made a grid of 100 squares then mark each row and column with any random numbers basically you should have people filled in these blocks before labeling them