Manual row-splitting is an advanced research function unique to CodeFinder. It allows you to force the program to divide the ELS of the center term in the matrix by 2-11, as selected. When it row splits, it re-matches the terms to the new display. You have to double click on the term in the Results list to display the new row split matrix.
Here, the center term, be'er neft (oilwell) is displayed at an ELS of 1036. This display occurs when the row splitting function is disabled, and is what you want to look at when first doing a matrix.
Now, lets row split it and the menu looks like: 
The following three gifs show a row split of 2, of 4, and of 7.
In each case, we can directly go from a row split of 2, to 4, then to 7 and back to 1036 by selecting disable row splitting. In each case, the program rematches other terms to the new center term display, giving you perhaps a much better matrix. It's easy to use, and gives the codes researcher a powerful new way to achieve superior results.