Originally Posted by PetzLUX

There is an error in your math. 2017 is not your "dead year".
If you status is valid till 02/2019, you can requalify in 2017 or 2018.
If you do in 2017, then 2018 is your dead year. If you don't in 2017, you still have the possibility in 2018.

Just remember: requalification is possible once during the 2-year-validity of the status.