I normally watch a lot of LCS and OGN (Korean league) LOL games.   
Sometimes the two teams plays well, but, even playing well, one team lose at the teamfight and lose the game.
Or one of the team can't engage well or they only get poked.

And at the last of the game, they said that they lose cause they have bad picks.

All the champions have their advantages and disadvantages but.. the picks can make you lose the game?


And what strategies are they using? Cause they not always do a "Wombo combo".