The locations down the field basically represent 0 or less yards (a stuff), 1 to 5 yards, 6 to 15 yards and 15 or more yards. So if it was determined the runner was tackled in zone 3 down the field, we would then determine how many yards he got from 6 to 15 yards and that is based on the results of that initial check to see if he was tackled. When we get into the 15 or more yards, additional checks are used to determine tackle chances incrementally down the field. ?
I've always suspected this was the case since I started generating these kinds of statistics
http://www.whatifsports.com/forums/Posts.aspx?topicID=428806&page=5
Now I know, so thank you :)
So since you've been looking at it, here's a question for you. Why are there more 5 yard runs than 4 yard runs? I realize that's not the case with the stats I just linked, but at some point, things changed and now there are consistently more 5 yard runs than 4 yard runs. It kinda seems like maybe the locations are actually <1, 1-5, 5-15, >15 where the two middle locations overlap at the 5 yard mark.
And if you're feeling really generous, I think the thing that everyone would like to know is if our guy gets tackled in the 1-5 yard range, what determines if it's a 1 yard gain vs a 5 yard gain?