Mugunus,
Each checkride is governed by the associated Airman Certification Standards (ACS). Here is a link to PDFs of these. https://www.faa.gov/training_testing/testing/acs
Come checkride day, the examiner will use the ACS like a checklist to ensure that your skills and knowledge are satisfactory.
While perfection is not the goal, there are some things that will need to be memorized and applied like laws, memory procedures, emergency procedures, aircraft limitations, etc. and there are other things that just need to be performed within the specified tolerances, which you’ll find explained throughout the ACS.
Here is another article worth reading: What does an ATP student need to do to be successful? - #4 by Chris
Tory