Green’s Dictionary of Slang

(orig. sporting) an absolute failure, lacking any chance.

1879		‘’Arry on Crutches’ in Punch 3 May 201/1: Oh! I tell yer the Toffs wasn’t in it, old mate.
1881		‘’Arry on Woman Rights’ in Punch 2 Apr. 156/1: Cheek? Bath chaps ain’t in it, my pippin!
1887		Cumberland Mercury (NSW) 28 May 4/6: [S]o far as flowing bowls are concerned the West-enders are ‘not in it’.
1890		Daily Trib. (Bismarck, ND) 8 Dec. 2/3: A dozen of the current bits of slang have originated in that way [i.e. in plays], the latest and perhaps best known at present being ‘he’s not in it!’.
1900		Punch Jan. 1737: Lor! Ain’t those boxes of Khaki Soldiers selling like wildfire! We ain’t in it with our Red Coats.
1905		‘Doss Chiderdoss’ ‘A Polyglot Policeman’ Sporting Times 1 Apr. 1/4: That rozzer isn’t in it, and he hasn’t scored a chalk, / He’s fair gone on her, but cannot give it lung; / For, through having everlastingly to jabber foreign talk, / He’s forgotten how to speak his native tongue!
1910		Bulletin (Sydney) 13 Oct. 11/3: Touching the question of a naval base in North or Nor’-West Australia, King Sound is not in it with Port Darwin, which bristles with advantages.
1923		Ade College Widow 50: You ain’t in it at Atwater any more unless you’ve got a dress suit.
1931		A. Bontemps God Sends Sun. 68: Shucks. That nigger ain’t in it.
1936		A. Russell Gone Nomad 28: Donkeys, also in common vogue for pack purposes and cart work on some of the runs, were not ‘in it’ with mules.