The MLB's official game balls manufacturer is changing the ball, possibly impacting players' performances across the league. The ball will be a little smaller, so it reduces drag and will carry more. But, it will also be less bouncy, as they deaden the ball by reducing the tension in the winding. 

I remember that ball adjustments happened in South Korea as well, but the effects were different than expected, and made it harder to hit home runs. Is this correct? Can someone tell us about what happened in the KBO so we know more or less what to expect in the MLB?