I already posted in the Rules-section. Now I want to show an alternative rule for measuring interceptions, that clears up with the problems I had in the other post.
The main problem ist, that there are uncertain situations, because the range ruler has to go through the middle of the field of the thrower and the catcher. Even a slight difference in "measuring the middle" can make a difference between intercepting or not.
So the rules are clear, but the process in practice isn't.
For this new kind of measurement you only need the range ruler, so it can easily be used with a standard game and also be used with bigger (self made) boards, where you perhaps aren't sure if the (mostly) bigger range ruler is in wide exactly the proportion of the original one.
Now, the interceptions are measured from the center of the squares. So i asked myself, why not take the corners of the square? The corners are marked on each board and not like the "invisible middle" of a square in the eye of the beholder. This would make measurement a lot more clearly and leads to an easy procedure:
W is for thrower (german Werfer)
F is for catcher (german Fänger)
but it doesn't really matter, who is thwrowing and who is catching the ball.
1. Where are catcher and thower standing?
2. Choose the corners of the squares, that are at the farthest outside and connect them. In the graphics, these corners are connected with lines.
3. Each field, that is intersected by one line or touched (in 1 point as in graphic 3 or as part of a segment as in graphic 2) can intercept.

You can use everything, that looks like a matrix somehow to measure interceptions besides the board. Even with your eye, by regarding the line from one corner to the other you can easily check, if the square of the opposing player is touched or intersected.
I proposed this new method for our tabletop league and i am sure, it works a lot better than the old rule. Perhaps it is not 1:1 equal, but therefor it's clear right now and can controlled by everyone in a very easy way.
Greetz,
gan