Turns out I forgot to count Anderton's cup games, meaning he actually averaged 33 appearances a season for 18 years, totalling almost 600 senior games.
A random comparison with Peter Schmeichel shows that the Dane averaged 35 appearances a season for 22 years.
Patrick Vieira averaged 32,6 appearances a year in 18 seasons.
Paul Ince: 33 appearances a year for 20 seasons (his four appearences in the last two seasons of his career not included).
Lee Dixon: Exactly the same as Ince.
Mark Hughes averaged 30,8 appearances a year for 22 seasons.
Andy Cole: 28,2 appearences in 19 seasons.
There's nuances and context here, obviously.