Fair and square

Fair and square：Square可以用做名词，也可以用做形容词。用做名词的时候，它的一般解释就是：四方块。用做形容词的时候可以解释为：正直的，或者是光明正大的。

eg: Jack won the race last week with flying colors. But other athletes suspected he had taken drugs before the race. I know Jack well - he's a person with high moral standards. I'm sure he won the race fair and square without any cheating.
杰克上星期在赛跑中以优异成绩获胜。但是，其他运动员怀疑他在赛跑前服了药。我很了解杰克。他是一个道德标准很高的人。我肯定他是老老实实取胜的；没有任何欺骗行为。