private static int compareWaves(ArenaPlayerStatistics s1, ArenaPlayerStatistics s2) {
    int s1wave = s1.getInt("lastWave");
    int s2wave = s2.getInt("lastWave");

    if (s1wave == s2wave) return 0;

    return (s1wave > s2wave ? -1 : 1);
  }
  private static int compareKills(ArenaPlayerStatistics s1, ArenaPlayerStatistics s2) {
    int s1kills = s1.getInt("kills");
    int s2kills = s2.getInt("kills");

    if (s1kills == s2kills) return 0;

    return (s1kills > s2kills ? -1 : 1);
  }