What defines winning and losing

In the patch notes for the latest patch it says http://imgur.com/kl2LBjG I was just wondering what riot used to define losing is it a mix of things, kills, towers, or gold. At first to me gold sounded like the best way but what about when the enemy team caps or they don't know how to get objectives (are too kill focused). so, I was thinking it would be a mix and I was just wonder what that mix was and if we could even find out or if it was like the YouTube algorithm and well never know or if I'm just overthinking this all and it's just gold thank for your time.