unknown quantity

But when he quit, that number jumped to 9%, reflecting the fact that Harris was an unknown quantity to many Americans.

While most analysts believe Beijing does not have a favourite in this race for the White House, many would agree that Kamala Harris is an unknown quantity to Chinese people and the country’s leaders.

Newcastle are still a bit of an unknown quantity for me because I can't say I've been particularly impressed by them so far.

Kamala Harris was an unknown quantity to leaders here and she still is, even after the debate.

They will be an unknown quantity with very little Premier League experience in their squad, and an exciting up-and-coming manager in McKenna.