Green’s Dictionary of Slang

1. a huge and resounding success, also applied to any notably exciting public event, e.g. a sports event, a speech [? f. a party so riotously enjoyable that one ends up by burning down the barn in which it is held; note Mathews, Dict. Americanisms (1951): ‘Barnburner, A member of a faction of the democratic party in N.Y. State (c.1840–50) so zealous for reforms that they would “burn the barn to get rid of the rats”’; this faction was otherwise known as the Young Democracy].

1934		‘Miscellany’ AS IX:3 237/1: A barn-burner is an exceptionally good hand [in bridge].
1957		M. Shulman Rally Round the Flag, Boys! (1959) 152: All the Dub Hotchkisses looked at him with [...] awe. ‘A barn-burner,’ said one.
1963		A.S. Fleischman Venetian Blonde (2006) 155: [of hands of cards] I dealt him one barn-burner after another [...] The whole thing looked like a winning streak.
1968		T. Wolfe Electric Kool-Aid Acid Test (1969) 367: The story was a real barn burner, Secret Interview with Fugitive Wanted by FBI, with all the trimmings.
2014		Ruderman & Laker Busted 113: Next came Bochetto’s turn on the podium. [...]. The supremely confident Bocchetto was spooling out a barnburner.

2. an expert, a highly competent person.

1971

Current Sl. VI.