YOU SAID:

I am the best player to have ever played sports

INTO JAPANESE

私はこれまでスポーツをした中で最高の選手です

BACK INTO ENGLISH

I'm the best player I've ever played in sports

INTO JAPANESE

私は今までスポーツでプレーした中で最高の選手です

BACK INTO ENGLISH

I'm the best player I've ever played in sports