DALLAS -- If you judge just by scoring average, March has been O.J. Mayo’s worst month in a Mavericks uniform by far. Yet coach Rick Carlisle considers Mayo a much improved player. The fact that Mayo’s averaging only 12.8 points per game this month – a drastic drop from the 17.9 he averaged before the All-Star break – doesn’t concern Carlisle at all. While Mayo is taking a lot fewer shots, this has been his most efficient month.