on a roll 连连成功；连交好运

【例句】
I made a name for myself and I was on a roll, I couldn't see anything going wrong.
我靠自己的能力成名了，接二连三地获得成功，我觉得一切似乎一帆风顺。

When he won one game after another, it was obvious he was on a roll.
当他赢得一场又一场比赛时，很明娩他正在连续交好运。