How can a candidate in the over 50 age group increase his or her chances of applying?

When applying as a candidate of the age group over 50, you should emphasise your strengths. There may be many of these, for example:
Experience

You have a wealth of experience that younger people usually do not have. This background creates a self-confidence that helps you to find a new challenge. You know what you can do and what you want.
Reputation and network

In the course of your professional life you have already been able to collect a number of references. You have an extensive and resilient network that could possibly be an advantage for a new employer.
Clarity

You can specify your ideas, strengths, interests and values. If your ideas coincide with those of the company, you will find together.