OP NOTE: Whoops! As u/TragicvLoss pointed out, am missing a pair of missions for 100 Stamps each. Will rework all this and post again later. Thank you for your catch!
TL;DR: Just playing daily nets you the Tier III reward. Playing 20 matches either at the tier 2-8 or tier 9-10 for most of the event will net you the tier IV and V rewards.
New event time! Breakpoints are the following, with no restriction on winning/losing but to be in the Top 10 of your team:
- 700: Consumables, Progression, and Customization
- 1400: Consumables, Equipment, and Customization
- 2100: Consumables and Fragments
- 2600: Equipment, Slots+Premium, and Crew
- 3000: Premium, Tank (T-34-85M) and Tank (STRV M/42-57)
Missions per tier break-up are:
Play 1 battle, tier 2 and above:
- 100 Stamps for 1 battle
Play 1 battle, tier 2 and above, verified military members only
- 100 Stamps for 1 battle
Tier 2-8:
- 10 Stamps for 10 Battles in Top 10
- 20 Stamps for 20 Battles in Top 10
- 30 Stamps for 30 Battles in Top 10
- 60 Stamps total for 30 Battles in Top 10
Tier 9-10:
- 20 Stamps for 10 Battles in Top 10
- 30 Stamps for 20 Battles in Top 10
- 40 Stamps for 30 Battles in Top 10
- 90 Stamps total for 30 Battles in Top 10
Estimating 7min average survival time and that you're getting into the top 10 about 66% of the time (numbers purely for calculation; feel free to wrangle them as appropriate). Also that you aren't military. Keep in mind that you accomplish the 10- and 20-battle missions by the time you finish the 30-battle one, so you only need to calculate the time take on the last one to gain all previous Stamp rewards:
- 1 battle at tier 2+ = 100 Stamps
- 30 battles in Top 10 / 0.66 = 45 battles rounded
- 45 battles at 7 min each = 5.25 hours played per tier break-up
- 2 tier break-ups per day (at 150 Stamps total) at 5.25 hours each = 10.5 hours daily
- 150 Stamps daily for 10.5 hours of play
- 250 Stamps daily for 10.5 hours of play, including the initial mission
- 190 Stamps daily for 5.25 hours of play, including the initial mission (tier 9-10)
- 160 Stamps daily for 5.25 hours of play, including the initial mission (tier 2-8)
Event runs from Mar 5 to Mar 29.
For doing both tier-battles per day (10.5h). Day values rounded up:
- 24 day run total at 250 Stamps daily
- 12 days for 250 Stamps per day = 3000 Reward level
- 11 days for 250 Stamps per day = 2600 Reward level
- 9 days for 250 Stamps per day = 2100 Reward level
- 6 days for 250 Stamps per day = 1400 Reward level
- 3 days for 250 Stamps per day = 700 Reward level
For doing just the tier 9 tier-battle per day (5.25h). Day values rounded up:
- 24 day run total at 190 Stamps daily
- 16 days for 190 Stamps per day = 3000 Reward level
- 14 days for 190 Stamps per day = 2600 Reward level
- 11 days for 190 Stamps per day = 2100 Reward level
- 8 days for 190 Stamps per day = 1400 Reward level
- 4 days for 190 Stamps per day = 700 Reward level
For doing just the tier 2 tier-battle per day (5.25h). Day values rounded up:
- 24 day run total at 160 Stamps daily
- 19 days for 160 Stamps per day = 3000 Reward level
- 17 days for 160 Stamps per day = 2600 Reward level
- 14 days for 160 Stamps per day = 2100 Reward level
- 9 days for 160 Stamps per day = 1400 Reward level
- 5 days for 160 Stamps per day = 700 Reward level
For doing one battle, tier 2+, per day (7min). Day values rounded up:
- 24 day run total at 100 Stamps daily
- Not possible = 3000 Reward level
- Not possible = 2600 Reward level
- 21 days for 100 Stamps per day = 2100 Reward level
- 14 days for 100 Stamps per day = 1400 Reward level
- 7 days for 100 Stamps per day = 700 Reward level
Note: This only covers missions run out of TankRewards.com, and not any of the extra ones that should be added within the game (like the upcoming one for 200 Stamps in 3 days time).