When you win, you win big, but when you lose, you just keep losing.
When you're up, you're really up, but when you're down on your luck, you're really down.
ーWhen you win, you win big, but when you lose, you just keep losing.
「当たるときは当たるが、負けるときは負け続ける」
ギャンブルのことを言うなら win と lose を使って言うと良いでしょう。
ーWhen you're up, you're really up, but when you're down on your luck, you're really down.
「当たるときはすごく当たるが、ツキが落ちるときはすごく落ちる」
ギャンブルなどで up と down を使ってもよく言います。
ご参考まで！
カナダ 
