Maxis numbered The Sims Online patches with four integers. The first represents the games' chronological release, the second was the patch version, and the last two were major or minor builds.
Before EA-Land, patches in The Sims Online depended on the city. All production cities were on got the same version, Test Center was normally ahead by one patch, while Betaville used a different chronological version. EA-Land carried over Betaville's chronological version but dropped Free Will.
Test Center and all production cities were based on 1.x while Betaville used 2.x. Due to the different chronological releases between the two cities, Betaville was always exempted from updates that came from Test Center. A third server was introduced under EA-Land as TC3-Test. Interestingly, TC3-Test was ahead by yet another one chronological version but shared updates as Test Center 3.