Mastery stats are used to track and reward long term black ops activity. There are both Spy Mastery and Wizard Mastery stats/rankings.
Your dominion gains mastery during wartime via successful spy and wizard ops. The base amount gained is 1/10th the amount of infamy gained by that operation. Additionally, you receive a bonus when targeting other dominions with a similar or higher mastery rating.
- +1 when your target has a higher mastery rating (target also loses 1) - +1 when your target has a mastery rating within 100 points of your own (target also loses 1) - No mastery is rewarded when your mastery rating is 500+ points higher than your target
For every 100 points of combined spy and wizard mastery you have acquired, 50 points is added to your minimum infamy after the hourly decay (capped at 500 for each type). Therefore, after generating the equivalent of 1000 maximum infamy 20 times over the course the round, you would have a permanent platinum bonus of ~5.77% (plus ~2.31% to secondary resources) and it would be extremely easy to keep your infamy 'topped off' for the maximum bonus.
Examples: - 25 spy mastery + 75 wizard mastery = 50 minimum infamy (both types are combined) - 500 spy mastery + 150 wizard mastery = 300 minimum infamy (rounds down to nearest 100) - 1000 spy mastery + 500 wizard mastery = 500 minimum infamy (spy is capped at 500)