ZRH-MAN comes in at 626 miles. but that only brings in only 1.5 for F and 1.25 for J.
As stated earlier the best thing could be to do FRA/AMS-NYC although that only earns 3 and 2.5 respectivley each way. The only thing I can think of is a RTW. FRA-JFK, SFO-HKG (SQ1)HKG-SIN. Then stay there till april then continue SIN-FRA and get in 10 points for the new year