Looks like the Astros cheated, and possibly won the 2017 World Series thanks to doing so.
https://www.latimes.com/sports/story...h-world-series
At issue now is the way Yu Darvish got clobbered so badly in both of his starts. He didn't strike out a batter either time. Now it's strongly suspected they were using electronic devices to pick up on the catcher's signs to him.