When Adalysis can't determine a winner ad (during the daily automated testing) because the ads in the adgroup perform similarly, it will let you know in the Audit Alerts/ Ads section on the dashboard.  

You can either leave the ads as they are, or replace the lower performing ad with a new one in an attempt to determine a clear winner.

Clicking on the alert will show you the list of adgroups that currently have this issue. Click on the adgroup to see the ads.