The group stage of the League of Legends World Championship concluded with expectedly close calls between European and North American rivals ending a tiebreaker twice. Attending the play-in turned out to be unexpectedly profitable, as No. 3 seeds (Team WE, Cloud9 and Fnatic) advanced while only one domestic league champion, Longzhu Gaming, made it to the quarterfinal.

Since the change of the groups format in 2014, only two No. 2 seeds have upset No. 1 teams in the quarterfinal: OMG over NaJin White Shield in 2014 and Origen over Flash Wolves in 2015. Most analysts would call the circumstances that contributed to the upsets extreme, but with two League of Legends Pro League first seeds in 2017, the quarterfinals are ripe for another surprise.

Longzhu Gaming vs. Samsung Galaxy

Kwak "Bdd" Bo-seong is heading to Gen.G Riot Games

Assuming Riot Games wants to give weekend priority to the most exciting matchups for local fans, the Thursday spot seems to indicate that Longzhu's clash with Samsung is a foregone conclusion. A 6-0 group leader falling to a South Korean team that escaped in second to an LPL team sounds nearly impossible.

But Longzhu isn't without its flaws. Domestically, it had the most success with a strong lane matchup setup, using pushing solo lanes to carry out a 1-3-1. At worlds, with only a small patch change, it fell behind more often and had to come back with powerful displays from Kim "PraY" Jong-in.

"We're trying to play with the current Ardent Censer meta," mid laner Gwak "Bdd" Bo-seong explained after Longzhu qualified for the quarterfinals. "It's also our fault that we weren't able to snowball as fast as we intended to. Playing against teams like GIGABYTE Marines -- it was a lot more difficult than expected to snowball in the early stage."

Part of the discrepancy comes from teams like Samsung Galaxy that share the top spots with Longzhu domestically. Rather than focus on snowballing, Samsung and SK Telecom T1 are known more for vision control later in the game and using teamfights or Baron from a deficit for comeback wins.

To some extent, getting a lead became easier for Longzhu in this environment, but that puts a lot of pressure on the duo lane. While many look to Kim "Khan" Dong-ha to snowball early, the stability of PraY and Kang "GorillA" Beom-hyeon ensures the duo lane keeps mid control while Khan side lanes later. In the final game against GIGABYTE Marines, Khan got caught splitting without mid pressure more frequently, and Longzhu couldn't find a comeback opportunity until it got pushed well into its own base.

It seems that matching Longzhu's bot lane with aggression is the answer to destabilizing the team's preferred setup, based on the GIGABYTE and Immortals models. That likely makes the lower early pressure methods of Samsung a poor candidate for victory, but Jo "CoreJJ" Yong-in spoke of Samsung looking to play a more aggressive early game after the team's first loss to Royal Never Give Up. And while Bdd wanted to avoid Korean teams in quarterfinals, counterpart Lee "Crown" Min-ho said the opposite.

"I think it would be most interesting to play against an LCK team in the quarterfinal," Crown said. "I would like revenge on both Longzhu and SKT."

Hungry to prove himself after the loss to RNG, Crown may find the aggression that made him look like the best mid laner in LCK in Spring.

SK Telecom T1 vs. Misfits Gaming

Taking down SK Telecom T1 will require more than the typical early aggression from Misfits. Provided by Riot Games

Given the 3-2 domestic record between Samsung and Longzhu in the LCK regular season, I would peg Misfits vs. SKT as the least interesting match of the tournament.

While Misfits have used a more aggressive approach to getting leads, the team has seemed to fear drifting away from engage support champions (first-picking Taric in part because of a limited number of engage champs that are also Ardent Champions), and its control of side lane later in the game is inconsistent.

"We understand the theory behind [side lane pressure]," Misfits coach Hussain Moosvi said, "and we've been improving on it since playoffs -- that's when we started actually looking into it -- so it's a lot better now than it was. But we still have a ways to go."

Given that control of side waves allowed SKT to stay in its first game against ahq e-Sports Club despite losing kills early, inconsistent side wave control could backfire for Misfits. SKT often manages to juggle side waves while maintaining vision pressure while Misfits feels the need to pull its top laner to contest Baron vision and give up pressure. This won't allow it to exploit one of the main weaknesses of a seemingly detached Heo "Huni" Seung-hoon.

But both teams put much more attention on mid and jungle. Kang "Blank" Sun-gu confessed he believes mid-jungle control dictates the game, and Misfits mid laner Tristan "PowerOfEvil" Schrage said the team found its playoffs stride only when he convinced his teammates to play more around him against Unicorns of Love.

Breaking open mid-jungle has been the key to destabilizing SKT. Misfits already has its eyes on that tactic.

"I think SKT would be fun because they're a team where their early game is not the greatest," Moosvi said, "but their mid-late game is strong, so it would be fun to see if we can improve fast enough in our mid-late game to actually abuse teams like that."

But, as a result, SKT feels a lot like another version of Team WE with a stronger mid laner and tighter vision denial in the late game. Even when Misfits set Team WE thousands of gold behind, it didn't have enough control of side lanes to close out the game. Misfits needs to learn to draft to abuse communication in top side and control mid-jungle, then carry out a 1-3-1. It has only a handful of days to do it.

Royal Never Give Up vs. Fnatic

play 3:19 League of Legends Worlds 2017 Group Stage Day 4 RNG v G2 A slow start gave way to a wild finish as Royal Never Give Up took on G2 Esports

The last time an all-Chinese and all-European team played each other in a best-of-five was in the Season 3 World Championship semifinals. The teams in question? Royal Club Haung Zu and Fnatic.

The organizations meet again with only one player retained in each team since the last faceoff: RNG AD carry Jian "Uzi" Zi-Hao and Fnatic top laner Paul "sOAZ" Boyer. Coincidentally, both teams have played increasingly more around Uzi and sOAZ as the tournament has progressed, setting up the clash.

For RNG, it's about ensuring kills and gold go to mid laner Li "xiaohu" Yuan Hao. Fnatic has played much less to mid and favored one side lane or the other, but an advantage on sOAZ can disrupt RNG's game plan.

"Every single game," Fnatic support Jesse "Jesiz" Le said, "we were still sort of selling our top laner, sOAZ. He was basically on tank duty. Literally, no matter what, even if he were to be able to counterpick, people just knew he was going to pick a tank. So we just tried to be more flexible and maybe set him up for success a little bit more."

In Fnatic's final games, more effort went to snowballing sOAZ, while Fnatic had previously played off only his passive pressure or his tendency to set up plays mid. As a result, sOAZ won the MVP of the day with flashy Gnar play. His preferred setup champions can often pull focus for Fnatic back to mid lane with teamfight pressure.

RNG may not exploit Fnatic's hole in mid lane control after getting xiaohu ahead early, but it will deny vision around the lane and make it harder for Fnatic to retake control as the game progresses. Once xiaohu is ahead, Uzi plays a safe mid control game to soft reset the waves, and the whole team looks for picks. That's where Fnatic's and RNG's strategies align -- and why who wins the vision game is so important.

"It's a big disadvantage" for a pick composition to lose vision control, RNG coach Huang "FireFox" Tinghsiang said. "They knew where we were, so it became really important to us to make sure we have a clean jungle with no enemy wards in it."

RNG will likely try to strangle out Fnatic by using a lead on xiaohu to contest vision and keep Uzi safe to get picks or teamfight later. Fnatic needs to press advantages in abandoned side lanes and accumulate objectives to prevent that from happening. Both teams will benefit from trading mid lane and side lane control, but it's all about which team will make the lead count in transferring pressure to compensate for loss.

Team WE vs Cloud9

The play of Nicolaj "Jensen" Jensen will likely be a tipping point in Cloud9's League of Legends World Championship quarterfinals matchup against Team WE. Provided by Riot Games

Pointing to how both Team WE and Cloud9 played against Lyon Gaming during the play-in stage proves to be an interesting exercise.

Team WE and Cloud9 both had more difficult games on red side when Lyon got a bottom lane advantage. For WE, that's because it plays most often around its bottom lane; for Cloud9, its bottom lane struggles to find equilibrium when its jungler is on the other side of the map, leaving it vulnerable to ganks.

But while WE gave up more kills to Lyon in close games, Cloud9 felt happier trading objectives. WE will make cocky contests that result in the deaths of its mid or bottom lane, but it will look to keep balance on other sides of the map and still secure objectives.

"When bot kept dying [against Misfits]," top laner Ke "957" Changyu said after WE qualified for playoffs, "we just kept cheering them on and telling them they were doing well; we were getting other things from it."

WE seem unperturbed by early deaths, something it has in common, to an extent, with Cloud9. What makes WE vulnerable, however, is mid lane. Cloud9 jungler Juan "Contractz" Arturo Garcia and mid laner Nicolaj "Jensen" Jensen haven't had the most stable journey to becoming one of North America's best mid-jungle duos, but C9 shines most when Contractz sets up Jensen early.

When WE play its best early game rotating duo lane competitions, it does so by taking jungle control and using mid pressure to rotate the bottom lane off a dive. If mid laner Su "xiye" Han-Wei falters, that doesn't happen.

If neither team snowballs, the battle between C9 and WE becomes about mid-to-late game teamfights, a setting in which both teams feel most comfortable. Team WE's aggro juggling and use of globals give it an advantage, but xiye's limited champion pool means even more responsibility falls to Jensen's shoulders.

Jensen has faltered under pressure domestically, but internationally, Cloud9 are North America's rock. If C9 gives NA its first World Championship semifinal appearance, it will be because Jensen, not Team SoloMid's Søren "Bjergsen" Bjerg, gives it to them.