The Buchholz metric indicates how strong has been the field the team has played so far. At the end of the season it essentially compares the strength of teams' divisions because that's where the biggest weight of their opposition comes from. The Berger stat effectively shows how well the team fared against the top and the bottom opposition respectively, the value above the 'expected' one indicates the team did better than expected against the better team and poorer against the bottom feeders and vice versa. The Remaining Strength metric is essentially the "Buchholz" of the remaining schedule. The metric is only calculated for Regular Season. If you do not see current season coefficients, that's because they are not calculated until at least 50 games have been played.