日本時間の8月11日 22時より6時間、一部の試合の接続をシカゴのゲームサーバーに振り分けるテストが行われます。テスト中の3～6時間はRanked Gameをプレイできません。
Service Status | League of Legends
On August 11, we are testing the NA game servers from approximately 6:00am to 12:00pm (noon) PDT. During this time, ranked will be temporarily disabled for approximately 3 to 6 hours.
redditへのRiotAhabの書き込みより
To further clarify - for this test we'll be pulling in a small percentage of live game traffic, and sending those matches to be played on the Chicago server rather than Portland.
It's an automated test (selection-wise), but will utilize live player connections. So yes, YOU will be testing the servers for us!