Keeping those things in mind, I can say that the count picked up 451 instances of "left and right" and 348 of "top and bottom." The data file it produces looks something like this: There's one line for each time I invoked the macro, and the two fields are first the split coordinate and then the amount of overlap.
The most obvious thing to do with a file like this would be make a scatter plot; but that has the problem that in some cases, a given exact combination of split coordinate and overlap value occurs many times.
Almost everywhere in Tsukurimashou that I have two components one above the other, I invoke a macro called . JP, but it may be pretty opaque if you're not familiar with the METAFONT programming language.) Each macro takes two numeric arguments specifying where to draw the line between the two halves of the composite character and how much to overlap them, and two "text" arguments ("text" is the METAFONT data type used for this purpose) which are fragments of code to draw the two halves. The macro takes the current drawing area, which is initially a square, calculates two new rectangular areas by cutting it in half at the specified coordinate and then shifting the boundaries to create the specified amount of overlap, and invokes the two halves it was given, each on the appropriate side of the line.
Here's an example of Each character is described in terms of a box that nominally (before these scaling-down operations are applied) covers x coordinates 50 to 950 and y coordinates -50 to 850.
A left-right split point of 480 is quite typical: when a character is made up of a left part and a right part, usually the left part is a little narrower.