Warding Mid Lane
In the game of chess, the winner is often determined by the player who can dominate the center of the board. League is very much the same. If you can control the center of the map you will win the game. The team that controls the center effectively cuts off side lanes from assisting one another and this leads to objectives (Dragons, Towers, Baron). Because you have control of the center your team can now flank, roam, and initiate winning team fights at will. This is the power of the center of the map. When vision is not properly placed around the Mid lane this can lead often to devastating and catastrophic results for your side lanes.