Ancelotti says the willingness of both players to take on different roles boosted their prospects.
"After 10 to 15 games, the opponents knew how to play against the Christmas tree and so the space in the middle of the pitch was very closed," Ancelotti told Chelsea magazine. "So from this moment we started to use wingers instead.
"We had the possibility to change a lot of players into different positions on the pitch so we made this our advantage.
"A surprise for me was Anelka in the role he played from the beginning until we changed the system in January," he adds. "He did very well alongside Drogba, when he did a different role, not just striker, and then he also did a good job as a striker when Didier was at the Africa Cup of Nations.
"Also Malouda was a surprise for me because after starting well he played with continuity in different positions - he played very well for all the season. For both players it was their versatility above all that surprised me, that they could perform different positions for the team."