whole new ballgame

Translations
совсем другая игра
Starting a business is a whole new ballgame compared to working for someone else.
Начать свой бизнес - это совсем другая игра по сравнению с работой на кого-то другого.
Definitions
A situation that is completely different from what one is used to or has experienced before, often requiring new approaches or strategies.
Words
whole

adjective
совершенно другая
new

adjective
новая
ballgame

noun
ситуация