On a Jamaican sound system the roles are split, and always have been: the selector — selecta in the dance — chooses and plays the records; the deejay is the one chatting on the mic over them. That split is why the words flipped when the culture crossed the water: what America calls a DJ, Jamaica calls a selector, and what Jamaica calls a deejay became the MC and, in time, the rapper.
The lineage is documented. Winston "Count Machuki" Cooper started in 1950 as the disc selector on Tom the Great Sebastian's sound, and working Clement "Coxsone" Dodd's Downbeat he became the first man to chat rhymes on the mic while selecting — the root of toasting and deejaying. That mic craft crossed to the Bronx with sound-system-raised emigrants like DJ Kool Herc, though Herc himself credits James Brown and Black American radio jocks as loudly as any Jamaican source. U-Roy carried the deejay style to the top of the Jamaican charts in 1970 with "Wake the Town" — the record Norman C. Stolzoff's study of dancehall culture is named after. Duke Reid's Trojan and Coxsone's Downbeat fought the great Kingston sound clashes of the 1950s before both men became foundational producers.
It reached Britain with the Windrush generation. Vincent "Duke Vin" Forbes — once a selector on Duke Reid's sound — built the UK's first sound system in London in 1955 from a second-hand turntable, a £15 speaker and an amp he wired himself; Wilbert "Count Suckle" Campbell ran the rival set. Because clubs routinely barred Black patrons, they played blues dances in Ladbroke Grove basements and front rooms — the rooms lovers rock, jungle, garage and grime all trace back through.
So calling someone a top selecta is a compliment about taste and knowledge, not technique: knowing the tunes, the deep cuts, the right record for the moment, the history behind the sound. That's the whole idea of this game — not how fast you can click, but how much of the music you actually know.
So — think you're a top selecta? Prove it.
Further reading: Lloyd Bradley, Bass Culture: When Reggae Was King (2000); Norman C. Stolzoff, Wake the Town and Tell the People: Dancehall Culture in Jamaica (2000); David Katz, Solid Foundation: An Oral History of Reggae (2003).