The 1981 Oakland Athletics won the AL West (technically the first half, as a strike split the season into two half-sesason division winners in each of the four divisions at the time) thanks in part to "Billy ball." That was the style employed by manager/GM Billy Martin.
As part of the fun, the Cubs and A's both wore 1981 throwback unis. There will be some people who hate these, because it's the internet and you can find someone to hate pretty much everything. Personally, though, I love both of these.
The powder blue:
And the yellow pullovers!
Another nice touch is the A's broadcast went with the retro graphics, too:
Love the retro-graphics the A's are using today to go w/the old unis, tho I'm having weird flashbacks. pic.twitter.com/0NOScqiVp6— Steven Goldman (@GoStevenGoldman) August 6, 2016
One more. Of course,a truly retro broadcast would cut the picture way down and make it fuzzy. pic.twitter.com/c5diipZC4s— Steven Goldman (@GoStevenGoldman) August 6, 2016
Beautiful work all around.