Cheong was born in Seoul, South Korea before moving to the United States at the age of 6.

[1] Cheong played online poker under the screen name "subiime," compiling winnings of $3.7 million.

[2] Cheong plays a classic ultra-aggressive game - with small raise sizes resulting in 5 or sometimes 6 bets before the flop - as manifested in the 2010 WSOP Main Event when he made the November Nine.

With the chip lead 3-handed, he six-bet all-in with A♠ 7♥ against the Q♣ Q♦ of Jonathan Duhamel and lost what was at the time the largest pot in WSOP history.

[6] Cheong finally won his first WSOP bracelet in 2019, outlasting a field of 6,214 in the $1,000 No Limit Hold'em Double Stack event to earn $687,782.