The suite cover most all of the major openings and systems, as well as types of positions. The openings also appear according to their frequency in actual play, therefore the number of Sicilians, for example, is actually proportionate to the frequency they are played compared to other openings, etc. This was done via database statistics in Mega Database 2010 with 4.5 million games.
Beyond the actual openings, I have also strived to include all the major types of formations, such as a stonewall, a hedgehog, an isolani, a KIA, etc.
The positions are reasonably flexible in that many lead to forks in theory where the engines can choose the direction they prefer. For example, the Alekhine position stops after 1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. Nf3
where theory indicates g6, Bg4, or dxe5 as the main continuations. I tested the major engines and they will choose all of those moves, so depending on the time control, or the engine, all lines can appear. This isn't always true for all openings. For example in the King's Indian Saemisch, stopping after
where main theory branches off to e5, Nc6, Nbd7, c5, c6, or a6, I was shocked to see the engines all insist on playing Nfd7, and none of the main lines, even after minutes of thinking.... so in this case, I chose 6...e5 7.Nge2 c6 to represent the Saemisch, after which a new fork appears, and here the engines are both logical and varied in their choices.
There are 50 positions in all, leading to a round 100 games. All positions have been tested with at least 5 top engines, each for a couple of minutes to be sure variety and theory were there. Needless to say, a lot of work went into this. I hope you enjoy it.