It is indeed confusing that both leagues share the same logo and are part of the 2. Bundesliga (second highest division in Germany). Furthermore it was not a good idea to name the leagues Pro since their are (especially in ProB) not only pro players. The mess is perfect when you remember that the french leagues are also named ProA and ProB. But while in France the first division is called ProA and the second ProB, in Germany the BBL is the highest level league in Germany.
To make it short:
ProA = second division
ProB = third division
To explain some of the differences I (finally) wrote a small piece that can also be found in the section League Facts.
ProA and ProB
In 1975 Germany’s second league was founded. 32 teams were divided into a north and a south division and played their own competition (so there was no north team ever playing against a south team). At the end of a regular season the champion of each division was promoted to the BBL (first division). Ever since the 2007/08 campaign the second division changed that classification and grouped teams into a ProA and a ProB section. Now the best second division teams play in the new grouped nationwide ProA and those teams who are too far away from a pro infrastructure compete in the ProB league. In fact the ProA is now the second highest level league in Germany and ProB is the country’s third league.
But check out the details to understand the differences between both leagues:
In ProA compete teams that have the aim to compete in the BBL sooner or later. Besides the sports part the clubs need to meet demands like a parquet floor, an arena with room for +1500 spectators and at least a 350.000 € budget. Every ProA team must play with two german players on the court at any time. Currently the league comprises 16 teams from all over the country. At the end of the league stage the top two teams qualify for the Basketball Bundesliga (BBL) and the teams positioned 15th and 16th are relegated to a lower league. For the 2011/12 campaign the teams agreed to have play-off competition to crown a champion and a runner-up that will move up to the BBL.
Click here to see the ProA homepage.
Unfortunatly there is no english version. But here you can find some interesting numbers:
The ProB was also a nationwide league from 2007-2010. Since this season (2010/11) the league is divided into a north and a south division. You can find many teams here that are far away from professional standards. The only real restrictions here are that at any stage of the game three german players must be on the court and the teams need to play in an arena for at least 500 spectators. Each division has 12 clubs and the teams finishing the season in the top 8 qualify for the ProB play-offs. The first of the south plays against the eighth of the north, 2nd vs 7th, etc. At the end of the play-offs the two best teams will be promoted to the ProA league. The teams that finish the regular season between 9 and 12 have to compete in play-downs and the loser of the best-of-three games will be relegated to Regionalliga (4th highest level league in Germany)