The performance summaries and charts are based on two metrics: TD30 and TD7. These are historically weighted measures of how much territory a faction has held.
Each “continent” is fought over by two factions, and contains 17 territories. One territory will always be contested, but the other 16 are owned by one of the two factions. If the factions are perfectly balanced, then they will perpetually hold 8 territories each. This is assumed to the be the “balanced point”, and set to zero.
Thus, if a faction holds 10 territories, it holds 2 more than the balance point, which is denoted as a score of 2. Negative scores are where the faction holds less than 8 territories. These balance scores are recorded in Balance Tables, one per faction. For example:
These can then be summed to provide a total balance of territories held over that time period, a metric called “Territory Days”, or TD. The more territories held at one time, the higher the TD, and the longer that positive territories are held, the more the TD grows.
Thus we arrive at the two metrics used: TD30 is the sum of the territorial balance over the last 30 days, and TD7 is the sum of the territorial balance over the last 7 days.
Obviously, TD7 is more volatile than TD30. By looking at both scores, you can see if the Faction is trending up or down in performance, and get a feel for how much the TD30 is likely to change over the next week. For example, on 23rd December 2016, the Orks had a TD30 of 11 and a TD7 of -13. This means that the Orks performance is dropping from a medium positive balance, and is likely to become negative unless they turn things around.