We utilize lots of resources to generate relevant analyses. The analysis is spread out over several high-powered computers, and every move is analyzed for 5 seconds at full power. As such, processing a game with 40 moves (80 half-moves) only takes about 10 seconds.
We also use one of the most powerful engines on the market: Stockfish 7.
Of course, from one analysis engine to another or from one computer to another, the results may vary, but we have made technical choices so that the analysis will fulfill its goal: to give the trends in the game, and the strengths and weaknesses of both sides.