Stats Criteria: What makes a game count? What makes a game a save?

I've seen varying info about this, and my experience has shown to be inconsistent, so I am hoping u/LuckySpammer or someone else informed can answer these questions.

Please settle the criteria for a game counting W/L and Save.

ie:

• time remaining in a game

• time spent in a game

• score upon joining

• team balance

• anything else that matters...

Stats on, obviously.