The season of shot callers
I think this season has been the biggest display of how important team cohesion and shot calling is to League of Legends. It is so amazing and has been a really different game to watch. Think about it, the top teams are all defined by their leadership just as much as they are their star players.
I may get flamed for this, but SKT didn't look as good (although that may just have been samsung having two amazing teams) season 4 as they did season 3 and do season 5. What changed? Their captain. Season 3 they had Poohmandu shot calling and the team came back even from some bad games. Season 4 they lost their captain and didn't seem to fully recover. However, Marin was on the sister team struggling, probably in part bc of the pressure to be the "Faker of top lane" and be the star of his team. He's looked great this season w/ Faker to take the pressure off and let him just be a consistent top laner rather than the star, and Marin as captain seems to have brought a lot to SKT in terms of them bouncing back in cohesion.
Yellowstar rebuilt the entire team and Fnatic has done great two splits in a row. 3 players were LCS rookies 2 splits ago, and Rekkles floundered on Elements. The team has great cohesion though and Yellowstar provides some veteran leadership that helps the raw talent on Fnatic gel and succeed.
Xpeke was though of as one of the weaker links in Origen mechanically, but he built the team from scratch and they have become dominant after on split of experience together. Soaz helps anchor the team for experience, but my guess is Xpeke provides much of the leadership for that team and it wouldn't look the same w/out him.
CLG has fallen apart so many times no thread is safe, but w/ a strong mid laner and perhaps the first split w/ minimal internal drama it seems (lots of external drama to make up for it) the team finally has some cohesion and players can trust each other as a team. The result is a shot at the first time ever an NA team making it out of groups in first place (at least I think it's the first time, but this is also deceiving because past seasons had a team seeded in for bracket so maybe season 2/3 it would have happened if the strongest NA team was in groups.
C9 is perhaps the best case for shot calling and cohesion making the difference ever. W/ a top laner who has been down by a lot in both games so far, and a jungle who hasn't really had a huge impact on the game pre six (plus is relatively new to the role!) they have still been winning games in convincing fashion. This season has looked like a great argument that Hai should have switched to jungle years ago (his champ pool always seemed to limit him slightly in mid, and even if he doesn't have a huge early impact Meteos was always known for being a bit of an herbivore jungle, so Hai being a bit farm focused early would be fine). God I'm scared for C9 when Hai leaves again. Hopefully he can bring in a solid jungle to really learn from him and be like the protege to the master shot caller and make the transition easier, bc NA needs C9 to be strong to keep the competition at the top up and grow the regional strength.
In contrast LGD and IG have had some players do well in lane and have crumbled in team fights and shot calling and really under performed this worlds.
All tribute to the captains/shot callers. They may not be flashy star players, but they certainly have been making the teams this season.