Complex sentence: In the 2015 season, they dropped to 10--6 and lost the NFC West title to the Cardinals, but they entered the 2016 playoffs as the number 6 seed in the NFC.
Split into simpler sentences: In the 2015 season, they dropped to 10--6 and lost the NFC West title to the Cardinals. However, they entered the 2016 playoffs as the number 6 seed in the NFC.