Dustin Browder of Blizzard Entertainment performed an interview with Team Liquid during the Battle.net World Championships.
Team Liquid is a very active team in competitive gaming with a strong focus on the Starcraft franchise; only recently did the team expand to include DOTA2. Their most notable accomplishment would likely be Liquipedia, a wiki containing a wealth of strategies and tactics for anyone in the public to utilize.
The interview was detailed in discussion of specific balancing changes — and most importantly — the thought and methodology behind them.
If you go on the Blizzard forums you will likely see a mass of posts which just do not get it. The purpose of a rebalancing is to slowly change unit stats just enough to alleviate a specific problem. Each small adjustment forces players to change their tactics which will get them thinking about new and innovative ways of winning. When a player comes up with a new tactic you will then get an oscillation between the races in the matchup as either side figure out how to overcome the other all the while begging for nerfs and buffs.
If you are interested in understanding what it takes to be a game designer then it will be a half-hour well spent.