The Tier protection prevents you from dropping to a lower tier.
This feature automatically activates when your statistics point is deducted.
You will be able to see whether it has activated itself or not in the results screen.

The Tier protection is only activated in the following conditions:

[Tier protection]
- Tier protection is provided three times when at level V of each tier
- One tier protection is provided in Ⅳ - I steps
- One tier protection is provided for Ace and Conqueror
- If the total rating after a match is lowever than the current tier's minimum points, the tier protection will automatically be activated(when eligible)