Dependent validation list

I need a Dropdown list that only shows the names that are in an optional contest. The contest is CTP and if a player is entered then in another column it is marked with an "x". In the "Player Entered CTP" box is where I want the Dropdown that only lists those in the CTP contest.

I'm sure it will take a formula in the Validation List but I've researched and researched and can't wrap my mind around on how to do it.

See attached for sample workbook.

Thank you in advance!

Andy