“Double down” comes straight from blackjack. When you double down, you double...

https://telegra.ph/Why-Do-Native-Speakers-Not-Notice-Idiom-Origins-07-29

“Double down” comes straight from blackjack. When you double down, you double your bet hoping the next card seals the win. Learners often think it means “go all in” every time—no. It’s a calculated risk, not reckless throwing cash around. Play it smart.