During his Brood War career, Flash was known for being one of the best and most dominant players in the history of the game, winning six Starleagues throughout his illustrious career (four in one year as well as the OSL/MSL in the same season). At the 2012 MLG Spring Pro Circuit, Flash won the KeSPA Exhibition Tournament by beating Bisu 2-0 in the finals in dominant fashion.
Flash came on to the Brood War scene as one of the youngest progamers to be televised at 14 years old, in 2007. His popularity skyrocketed when he won the 2008 Bacchus OSL at age 15, crushing Stork 3-0 in the finals.
Flash's career eventually reached new heights in 2010, as he went on a stunning winning spree. During this year, he was in finals of eight premier tournaments, winning five of them: two OnGameNet Starleagues, two MBCGame StarCraft Leagues, and the World Cyber Games 2010.
Wings of Liberty
Transition to StarCraft II
Following KT's win in the 2010-2011 Shinhan Bank Proleague final, while recovering from surgery on his right arm, Flash started playing StarCraft II on the ladder and quickly reached the Master League. In April 2012, he was reported to be practicing SC2 again and to be enjoying the game. In early May, Flash was reported to be considering to switch to Protoss, but kept practicing Terran as remaining with the same race for the upcoming hybrid BW/SC2 2011-2012 Proleague Season 2 seemed more suited. The South Korean player also stated that, in his opinion, it would take him a year to reach the skill level of the current SC2 top players, and one or two more years to reach his Brood War level of skills. On May 12, a South Korean website released the first videos of Flash practicing StarCraft II, playing Terran on the ladder.
Flash played his first ever official StarCraft II match on May 20, 2012, as KT Rolster faced CJ Entus in the 2011-2012 Proleague Season 2 first round, which he lost to EffOrt. He secured his first victory a week later, defeating Team 8's BaBy.
In early June, Flash was one of the eight KeSPA-affiliated players to be sent to the KeSPA exhibition tournament at the 2012 MLG Spring Championship which he won in a dominating fashion without dropping a map.
First Forays into Major StarCraft II Tournaments
Since the OSL would also fully transition into StarCraft II, Flash participated in the 2012 OSL KeSPA Dual Tournament on August 7, 2012. Flash took down Ryul2 in game one, and then advanced in to the winners bracket to face Last. After taking down Last, Flash advanced in to the 2012 SC2 OSL Season 1 with a total score of 2-0. Flash was placed in group D with three Protosses, MC, BeSt and San. He went 3-0 to place first and make it into the round of 16. There, he faced Last in the first round. Despite initially going 2-0, Flash ended up losing 3-2 to Last and therefore end his first SC2 OSL run.
Flash made his debut in the GSL in Code A of 2012 GSL Season 4. After making it through the preliminaries after beating fellow KeSPA player soO, Flash played Killer in the first round of Code A, and ended up beating him 2-1. In the following round, Flash was defeated by Mini and sent to the Up and Down Matches where despite tying for second place with a score of 2-2, lose the tiebreaker and miss his chance at Code S.
As one of the top 24 players in the KeSPA Hybrid Proleague, Flash was given a spot in the 2012 MLG vs Proleague Invitational. He placed fourth among the KeSPA players with an overall score of 40 - 8, therefore securing a spot for him in the playoff bracket. There, he faced EffOrt in the first round in a rematch of the 2010 Korean Air OSL finals. After narrowly beating EffOrt with a score of 4-3, he moved on to face soO in the following round. There, he lost with a score of 3-4, placing Flash in the top 8 of the tournament.
Due to his success in the MLG vs Proleague Invitational, Flash was given a group seed to the 2012 MLG Pro Circuit Fall Championship in Dallas. In the first round, Flash played Grubby, which generated a lot of hype due to the clashing between two of the most dominant players of the original StarCraft and of Warcraft III. Flash defeated Grubby and TheStC with scores of 2-0. He went on to face NaNiwa and was defeated and fell into the lower bracket, where he faced HwangSin, who he defeated 2-1. In the final of the Group Stages he once again played NaNiwa in an extended series, Flash managed to turn around the 2-1 deficit to take it all the way to game 7, then on Tal'darim Altar, Flash opted to go for a 11/11 proxy barracks attack against NaNiwa's one gate expansion build. Despite scouting the push coming, NaNiwa was unable to defend the marine-scv push and ultimately lost. Flash went on to play the GSL champion Life in the Winners Round 1. In the first game, Flash opted for a marine-tank composition against Life's ling-infestor-brood lord combo. Despite falling behind in the early game due to some heavy Infestor harass, Flash capitalized on Life's mistake of a-moving a large group of Infestors into tanks. After cleaning up unprotected Brood Lords and Corruptors, Flash destroyed Life's bases, causing the Zerg player to GG. In the second game, both players went for a similar composition, but with some good defense and incredible macro, Flash weathered Life's constant attacks. With a switch to Ultralisks, Life looked like he might have been in a dominant position, but Flash persevered and ended up taking down the 15 year old Zerg player, and moved on to the top four of the tournament. In the semifinals, Flash played Life in his second extended series of the tournament, after Life came through the losers bracket by beating Heart. Despite starting off in the lead due to the extending series, Flash ended up losing four games in a row to the GSL champion for a score of 2-4 to take 3rd/4th in the tournament.
Flash played in Code A of the final season of 2012. In a repeat of last season, Flash made it to the second round of Code A once again only to miss out on another chance at Code S after losing a tiebreaker. Flash tied his Brood War rival Jaedong with a score of 3-2 in their Up and Down group, but due to his head to head loss against him, Flash would be denied entry into the Code S Wildcard group.
In the first match of 2012-2013 Proleague Round 1 (first all SC2 Proleague) he defeated Liquid`Zenio. In the second round, KT Rolster went up against EG-Liquid, Flash came out first for KT Rolster and performed an all-kill, the first of the tournament, taking out Revival, HerO, TaeJa and JYP and giving KT Rolster a 4-0 victory, securing their place at the top of the league.
Heart of the Swarm
Just 3 days after Heart of the Swarm launched, Flash competed in the 2013 MLG Winter Championship. In this tournament, he continued using his economic openings displayed in Wings of Liberty, and helped popularize the usage of Widow Mines alongside regular bio play. He was defeated by Life in the finals, dropping multiple games to large Zergling and Baneling busts.
Flash continued to use this style throughout Proleague and GSL Code S. In the first Heart of the Swarm Code S, rebranded as 2013 WCS Korea Season 1 Premier League, Flash was knocked down to Code A, or Challenger League, after going 1-4 in a Round of 16 group with PartinG, Life and INnoVation. He went straight back into Premier League by beating Avenge 2-0.
The following WCS Season, hosted by OGN, Flash again reached the Round of 16 before falling out, losing again to INnoVation. Falling to the final round of Challenger League, his opponent was EffOrt, whom Flash defeated handily 2-0 putting him back in Premier League for the next WCS season.
Shortly after the Third Season of WCS started Flash flew to Dreamhack Bucharest, Flash was seeded into the 2nd group stage, where he was put into Group F with Harstem, DIMAGA, and White, surprisingly to most Flash would lose to DIMAGA but still made it out of the group stage by defeating Harstem, and White.
The Third group stage would put Flash into a tough group that consisted of MMA, YugiOh, and Ryung, Flash would lose to both YugiOh and MMA but defeat Ryung, who he had faced before in the GSL, knocking him out of the group stage and ending his tournament.
Coming back to Korea, Flash would play in WCS Korea S3, Flash would ease his way through his Round of 32 group only losing 1 game to hyvaa. The Round of 16 would bring similar results as to Flash's previous seasons in WCS this year, he would lose to PartinG win against KangHo but lose to Maru, the times he lost were both with scores of 1-2, it was close but Flash would yet again be knocked out in the Round of 16.
Flash would fly out to another foreign tournament looking for victory, his time in New York however was short lived as he lost to Curious, struggling but still defeating State 2-1, and then losing against DongRaeGu 1-2 despite putting up a good fight.
Back in WCS Challenger league after his defeat in the Round of 16, Flash faced CoCa a player who had left the game but had come back, with people expecting good things from CoCa and people doubting Flash, things were simple as Flash crushed peoples doubts and defeated CoCa 2-0.
WCS Korea 2014 S1 introduced a change of format for Code A, with it now being groups instead of a bracket format. Flash was placed in group C with Leenock, YongHwa, and BrAvO. He fell 0-2 to YongHwa and 1-2 to BrAvO, resulting in Flash's fall out of Code A.
In the following season Flash re-qualified for Code A, but failed to make it through to Code S once more. This reinforced his apparent weakness in individual tournaments, where he has yet to see success since early 2013, contrasting with his strong and consistent performance in Proleague over this period.
However, in GSL season 3, Flash managed to qualify again, and broke through his Code A barrier, defeating Symbol 2-1 and Hush 2-0. In Code S, he was placed into a group with Solar, Dark, and Avenge, and swept Dark and Solar successively to top his group with a 4-0 record. He has been placed into Group D in the RO16, after not being picked by anyone in the newly reformed group selections. His group consists of three zergs- soO, DongRaeGu, and TRUE.
Despite disappointing Code S performances in the first half of the year, Flash impressed many with his performance in the SanDisk SHOUTcraft Invitational in June, where he advanced from the ro8 in first place in his group with wins of 2-1 vs herO and 2-0 vs Life. He would go on to face fellow Terran Bbyong in the semifinal. Widely regarded as one of best TvT series of recent times, Flash opened up the bo7 series with a 2-0 lead, showcasing excellent decision making and defensive play. In game 3, Flash played a mech style vs Bbyong's bio-tank. Out-maneuvering Flash's army, Bbyong managed to stim his bioball up into Flash's main, leaving Flash no option but to go for a base trade. The game became extremely even, with both players having a strong army but neither having much tech or economy remaining. Cleverly, Bbyong managed to build enough vikings to obtain air control, and added a few banshees which ended up winning him the game. However, Flash was undeterred, and proceeded to take the next 2 games and round out the series 4-1, knocking Bbyong down to the 3rd/4th place match and securing Flash a place in the final vs herO, who Flash had beaten in the group stage. With the first 2 games going to Flash, the stage looked set for the Ultimate Weapon to finally get a StarCraft 2 tournament win. Unfortunately it wasn't to be, as in the later games of the series, herO defended Flash's SCV pull timings again and again, always coming out on top. herO closed out the series 4-2, defeating Flash. Nevertheless, this event represented somewhat of a breakout performance for Flash in individual leagues, where he had shown little success since the early days of Heart of the Swarm. It remains to be seen whether Flash will capitalise on this in Season 3 of WCS 2014, and finally see success in the GSL.
Before his GSL RO16 group was played out, he had another foreign tournament to attend though, being IEM Season IX - Toronto which many considered to be the Starcraft highlight of year, with an incredibly stacked line-up. Flash was seeded into group D, the group that many considered to be the group of Death, with MC and Scarlett as his opponents and Life being seeded into it after qualifying through one of the Open Brackets! After first seeming to struggle against MC and losing 1-2 to him, Flash then went on to face Scarlett in the losers match and won convincingly 2-0 only to face MC again, who had fallen to Life This time Flash was able to take the BossToss down 2 to nothing. Moving on to the RO8 he was to face Snute, representing the foreigners of the tournament. Flash lost the first two games to the incredibly solid looking Snute and was now on the verge of getting eliminated by the Norwegian. However he ended up making the comeback and won the following three games, taking down the so-called best foreigner in the world, now moving on to face another Team Liquid player, by the name of TaeJa. After once again losing the first game, he went on to tie up the second game. The third match then became in incredibly close TvT macro game featuring Mech vs Bio that ended with Flash winning the game and taking the 2-1 lead. The third game then quickly ended with several mistakes by TaeJa and went on to the finals, where he would be facing his teammate Zest to fight for the Intel Extreme Masters championship and for his life at Blizzcon, that was still theoretically possible if he were to place really high at this IEM and in both KeSPA Cup 2014 and GSL Season 3. In an incredible final run, Flash then won 4-1 against Zest to win his first ever Starcraft 2 championship in a convincing fashion.
However, Flash's performance in the GSL just days later was decidedly less impressive. Despite being able to crush through TRUE with two early pushes and defeat him 2-0, he struggled in the winner's match against soO. The Zerg player took substantial damage in the opening stages of the first game from Flash's hellions and drop harass, but held on and managed to take the game in a display of impeccable macro. Although Flash would take map 2 in a back and forth game, he was unable to close out the series, losing 1-2 to soO and dropping down to the deciders match to face DongRaeGu. Despite being heavily favoured against the teamless Zerg, Flash again lost 1-2 to drop out of GSL season 3. With a subsequent 0-3 loss in the semifinals of the KeSPA Cup to herO, Flash's hopes of edging his way into the top 16 WCS players to earn a ticket to the 2014 WCS Global Finals at BlizzCon were ended.
- Flash holds the highest KESPA Point record ever, with 4,292.5 points in September 2010.
- Flash is the most successful player in the history of progaming in terms of qualification (to BW tournaments).
- Flash's widely accepted nicknames are "The Ultimate Weapon" and "God Young-Ho" or simply "God".
- The "Unimpressed Flash Meme" refers to a series of humorous image macros depicting Flash being unimpressed with various topics.
- After a failed burglary attempt, Flash decided to keep his Golden Mouse in a bank vault for safekeeping.
- Uses a ruler to set up his desk before a match 
- Starred in one of Khaldor's videos showcasing his APM.
- Flash was the Most Valuable Player of the 2014 Proleague Finals.
- Flash is the second player (after his long-time rival Jaedong) to win a Premier tournament in both StarCraft: Brood War and StarCraft 2.
- Flash is a part of the Brood War quartet TaekBangLeeSsang
|In Premier Tournaments|
|2014-11-16||2nd||HomeStory Cup X||3 : 4||PartinG||$6,500|
|2014-09-13||3 - 4th||KeSPA Cup||0 : 3||herO||$4,895|
|2014-08-31||1st||IEM Season IX - Toronto||4 : 1||Zest||$10,000|
|2013-03-17||2nd||2013 MLG Winter Championship||2 : 4||Life||$15,000|
|2012-11-04||3 - 4th||2012 MLG Fall Championship||2 : 4||Life||$7,250|
|In Major Tournaments|
|2014-06-08||2nd||SanDisk SHOUTcraft Invitational||2 : 4||herO||$2,500|
|2013-07-02||2nd||2013 Asian Indoor-Martial Arts Games||1 : 2||sOs||-|
|2012-12-13||3 - 4th||MLG Tournament of Champions||1 : 3||Rain||-|
|In Premier Team Leagues|