Thank you Bertrand. One benefit of leaving a puzzle in the Rookie and Expert sections for an extended period is that it gives the Pros time to do the required research. Then, when the puzzle is moved up, it becomes a race to see who can file his answer first. Today I happened to be in the right place at the right time. Of course a Rookie or Expert could answer correctly before the puzzle is moved up, and the research expended is to no avail. Still, the research effort is not in vain, as it adds to one's store of knowledge in answering future puzzles.