In English, if something is a “tough call” it means it’s difficult or impossible to know what is the correct answer or opinion.
Some examples will help make this more clear: “I’m really not sure who is the better tennis player between Federer and Nadal. It’s a tough call“.
Some examples will help make this more clear: “I’m really not sure who is the better tennis player between Federer and Nadal. It’s a tough call“.
“He still loves his wife but they have a lot of problems. He’s not sure if they should stay together or get a divorce. It’s a really tough call.”
“Those two girls are both really hot. I’m not sure who I think is better looking. It’s a tough call“. I hope that helps!