“Double down” comes straight from blackjack: when you’re dealt decent cards,...

https://touch-wiki.win/index.php/Licensed_British_Online_Casino_MrQ_%E2%80%93_Gambling%E2%80%99s_Lingual_Legacy

“Double down” comes straight from blackjack: when you’re dealt decent cards, you double your original bet but get only one more card. In business or life, it means to commit fully, not hesitate