Green’s Dictionary of Slang

bullhead luck n.

very good luck.

1870		Bloomfield Times (PA) 24 May 2/5: As he raked in the winnings he would remark that luck was all his way [...] ‘Pure luck,’ said he, ‘bullhead luck, nothin’ else’.
1874		York Herald 20 Aug. 7/3: ‘What is bullhead luck?’ [...] In the oil region a man who eked out assistance on scrubby, stony hills [...] and then sold out to some wise speculator or 2,000,00 dols.
1879		Scribner’s Monthly Oct. 834/2: By exercising skill and judgement, or ‘bullhead luck,’ as an old veteran of the pass calls it, a little execution may be done.
1879		Leamington Spa Courier 20 Dec. 3/2: Talking about downright bullheaded luck [...] why that fellow beats anyone I ever heard of.
1893		Omaha Dly Bee (NE) 5 June 4/5: It is the common and accepted theory [...] what is denominated as ‘tenderfoot’ luck in mining communities [...] passes currency as ‘bullhead’ luck.
1894		Eve. Bulletin (Maysville, KY) 2 Oct. 4/3: The bleu chips all came their way. It was simply a case of bullheaded luck.
1898		Omaha Dly Bee (NE) 22 Sept. 9/3: [headline] Bullhead Luck at Poker. A Convincing Game at a Stop-Over Joint [...] A Foreign Pilgrim Who was Considered a Pudding but proved the Luckiest of Poker Players.
1903		London Dly News 20 Apr. 10/3: It is absolutely safe to put the cock-sure ‘exprt’ down aas a very unsafe guide, any biut of bull-headed luck he may have had in the past [...] notwithstanding.
1915		Coventry Herald 11 June 2/3: Within another half hour, what seemed to be sheer bull-headed, dumb luck brought a casual automobile to Mesquite.
1922		Northampton Mercury 27 Jan. 14/3: I’ll let you in on a secret [...] Bull-headed luck turned this trick.