public OnGameModeInit()
{
    SetTimer("ResetScore",1000,true); // Set a timer to reset the score at each second.
}

forward ResetScore(); public ResetScore()
{
    for (new i = 0; i < MAX_PLAYERS; i++)
    {
         if(IsPlayerConnected(i)) SetPlayerScore(i, 0);
    }
    return 1;
}