A Revisiting puzzle presents an earlier Foldit puzzle to be solved again. Revisiting puzzles are one of the most common types of Foldit puzzles. Generally, there is a new revisiting puzzle each week, with revisiting puzzles being about one third of all Foldit puzzles.
Most revisiting puzzles have been based on Foldit puzzles 52 through 165, which were first played between May 2008 and July 2009. A few revisiting puzzles have been based on puzzles from 2012 and 2013. See revisiting puzzle results for a complete list of puzzles.
Puzzle 52: Bacteria Energy was the first to be revisited, in Puzzle 700: Revisiting Puzzle 52 (Bacteria Energy), starting 10 April 2013.
Generally, the goal of revisiting puzzles is described this way:
- We are revisiting old Foldit puzzles so we can compare results to see how useful the recent additions to the game have been.
Some revisiting puzzles may form disulfide bridges. Early versions of Foldit did not specifically reward disulfide bridges. Many revisiting puzzles include a disulfide bridge filter, which awards a bonus, typically 250 points, for each disulfide bridge.
Most revisiting puzzles involve proteins which have published solutions which are available in the Protein Data Bank.