To clarify, we don't "choose" the companies on these lists. All the screens are based on set quantitative criteria, which are taken either from research papers that have explored and backtested a possible market inefficiency (e.g. low PE stocks), or from the writings of investing gurus such as Ben Graham or Joel Greenblatt.
If a given company isn't appearing on the screen, this means that it doesn't meet the quantitative criteria set out in that screen. You can see those criteria by clicking on the Rules tab for each screen. If you believe that this is a data error, do let us know.
The best way to answer this question is to use the checklist tool. At the bottom of the screen page you’ll see a link through to view the screen rules as a checklist. By entering the ticker you can see which rule it fails for.