American Airlines was the first airlines which introduced revenue management software to control and manage air fares in their reservation systems. Remember a guy from reservation department on AA talking at one of business TV program that more than 80% of fare pricing is controlled by revenue management software.

If I remember correctly, Hilton corporation was the first hotel companies to acquire revenue management software from American Airlines and used the software to control and manage their room rates. The software uses data from previous years reservation trends and predict demand for specific dates and specific room types.

It is pretty much impossible to make sense of air fare pricing, and same way it will be almost impossible for us human to understand room rate decision making of revenue management software by plotting room rates on spread sheet.