Gamasutra's Matt Matthews writes:
"Recently GameStop, the videogame retailer, added a new feature to its online storefront that permits filtering of its game catalog by the ratings assigned by the Entertainment Software Rating Board (ESRB). Presumably, a savvy parent shopping for an 8-year-old child can now browse for games rated E (for 'Everyone') and skip those rated E10+ which are appropriate for a slightly older audience.
I started looking at the number of games of each type per platform -- Nintendo DS, PlayStation Portable, Xbox 360 -- and it made me wonder what patterns I would see if I could visualize these distributions.
Fortunately, the ESRB has long provided a variety of means for searching its ratings database of rated games. After I compiled the data for several platforms, I began making charts of the distributions on individual consoles and handhelds. Those graphs revealed manufacturer-specific ratings distributions, and possibly even some evidence of how platforms have different strategies in different generations."