Zynga posted its Q4 and full year 2011 results today, citing its oldest games as the biggest moneymakers.

Average bookings per user (ABPU) rose 11 percent to $0.061 up from $0.055 in Q4 2010.  Zynga COO John Schappert called out five of Zynga’s older Facebook game franchises on the company earnings call as key bookings drivers. Expansions launched in Cafe World, FarmVille, FrontierVille and CityVille all increased bookings — and Texas HoldEm Poker continues to deliver record bookings even after four years on the platform. Advertising growth and pair conversion rates on social and mobile platforms also drove ABPU growth.

Younger games typically don’t contribute as much to bookings because they have a higher percentage of non-paying players in the mix. Zynga did claim one notable exception with CastleVille, however, despite the game’s late launch in Q4. Based on Zynga’s expectation of slower sequential growth in the first half of 2012, it sounds like Zynga expects its newer games — like Empires & Allies and Hidden Chronicles — to show stronger bookings as they age.

Some of Zynga’s newer games failed to perform as well. Mafia Wars 2 bombed in Q4, dropping more than 70 percent in monthly active users and more than 80 percent in daily active users during Q4. Other Zynga titles also saw traffic declines as a result of age, but Zynga reports that growth in CastleVille, Empires & Allies and other recently launched games off-set the losses.