As a TSM fan, I always groan to myself when....
I always groan to myself when Dyrus picks Hecarim or Rumble or carry top laners.
TSM's strategy is to lane swap because of Turtle's laning weakness. Hecarim sucks in lane swaps. So the strategy to fix that would be to give Hecarim TP/smite so he can get jungle xp as well. Dyrus doesn't TP/smite any champions competitively. And Rumble because he just always has terrible ults. His carry top laners always lose because they get camped because TSM's style isn't to ever help Dyrus.
I always groan to myself when Santorin picks Rek'sai.
Rek'sai for some reason always seems really lackluster on Santorin. Santorin's style is to gank early, but only continue ganking if it's successful. If he fails, he will just farm. Rek'sai sucks if you don't get going early. Also, Santorin's early objective control (and TSM as a whole) really is piss poor. Giving up dragons early is fine, but only if they make sure to take something else as payment, which they have not done at all in MSI.
I always groan to myself when Bjergsen picks Cho'gath or Urgot.
Bjergsen's Cho'gath is fine as long as his jungler and his top laner are doing well, but Dyrus usually gets a slow if not immediately destroyed start in the game. 4/5 games at MSI he gave up first blood. Again, that's fine as long as something else happens because of it. The champion pick mid lane means that Cho is sitting mid farming until 6 before he can actually do anything or have any kill pressure. Bjerg's style is to really get ahead at 10 minutes and then pressure the map--something he can't do on Cho. Sure, he might be winning in CS, but he'll just get ganked and lose his lead. His Urgot is also only effective when Santorin is really pressuring hard. It's one of the reasons I really like Santorin's Nidalee. He can both be aggressive and 1v1, gank early, splitpush, and support all in the same kit. Sure, it's not as good in the meta right now, but I think people have proven time and time again that playing a champ you are comfortable on and know you can make plays with is far better than just trying to play the meta picks.
I always groan to myself when Turtle picks anyone other than Sivir, Jinx, or Corki.
His Kalista is incredibly sub-par. He makes the wrong choices about when to jump in and when not to, and with the lane swap, they lose the incredible lane-bullying that Kalista brings, which Turtle just can't cash in on, especially against the world-class adcs of MSI. His Lucian is ok, but I think he just makes poor decisions with his positioning, and again, he just doesn't win lane. Ever. His Sivir is honestly really safe. He plays her well, and she's fairly forgiving with spellshield. Her ult helps his team win fights, something they completely rely on. His Corki is likewise very safe with some consistency of always bringing a certain amount of damage to the team. His Jinx is probably his most risky adc to play, but he does perform fairly well on her late game, with minor positioning errors and poor decision-making being his biggest flaws on the champ.
I always groan to myself when...
Who am I kidding? Lustboy is god. Any champion he picks, I feel like he makes plays on. The issue is when the rest of the team can't follow up. Then he looks like an idiot, even though he is LustCena, boy wonder.
At MSI, the compositions were:
Gnar (0/4/4) Rek'sai (1/1/4) Cho'gath (5/6/1) Sivir (0/2/4) Thresh (0/2/5)
Maokai (1/0/5) Sejuani (3/0/6) Ziggs (4/1/5) Sivir (3/0/7) Thresh (0/0/11)
Hecarim (3/6/1) Gragas (0/3/2) Ziggs (2/5/1) Kalista (0/7/3) Thresh (1/7/3)
Sion (2/8/1) Sejuani (3/3/3) Urgot (0/6/1) Corki (3/5/6) Bard (1/6/3)
Hecarim (0/5/2) Gragas (0/2/2) Cho'gath (1/6/1) Kalista (2/4/1) Thresh (0/2/2)
The only game in which none of the problem champs highlighted above were picked was in their easy win over the Turkish team. Not to say the champions were what made it easy, but it was a comfort pick.