It has been a while since Dani2 visited the forums so you are unlikely to get a response.
There is a description on what the leech value is and how to interpret the numbers in the top post of the Item inspector thread. A link is provided below. The information you are seeking is there. Look under the Leech Value header.
If you are interested into leeches you should give Item Inspector a try. It is designed for studying leeches. It has many advantages over Dani2’s script.
- It has a popup feature. You may go over your leeches reciting meaning and reading and you mouse over the item to reveal the answer. This will improve your study.
- Clicking on an item will open the item description page. This is handy if you have business with the mnemonics.
- You can play the audio for the vocabulary items.
- It is integrated with Self Study Quiz, which means you can get quizzed on your leeches at the click of a button.
- You can display all sorts of statistics about your leeches to get a better picture of your situation.
- You can set the filtering value for leeches with real numbers instead of integers as Dani2’s script require you to use. This will give you a much better control on what you would consider to be a leech.
Disclosure: I am the author of Item Inspector.