Written and first recorded by Don Schlitz (C&W #65 1978).
Other hit version by Kenny Rogers (US #16/C&W #1 1979 |UK #81 1985 |UK #22 2007).
From the wiki: “‘The Gambler’ was written by Don Schlitz who first recorded it in 1978, and charted at #65 on the Billboard Country chart with it. Kenny Rogers released his cover version in November 1978 as the title track from his album The Gambler and would go on to win the Grammy award for Best Male Country Vocal Performance in 1980. ‘The Gambler’ was one of five consecutive songs by Rogers to hit #1 on the Billboard country music charts.”
Kenny Rogers, “The Gambler” (1979):