IFHE and Cruiser and Battleship Plating Changes Free Commander Skills Respec

In Update 0.9.2, the thickness values of Cruiser and Battleship plating have been updated and the Inertia Fuse for HE Shells skill has been modified.

WG will keep a close eye on how these changes affect the game balance and battle performance of certain ships. If required, additional balance corrections will be applied to the skill and some ships to preserve their battle performance.

There will be a Free Commander Respec for 0.9.2 due to the IFHE changes.
You will need to go to your regional portal (Wows Web Site) when the Update Patch for 0.9.2 has been published (10/11 March 2020), and click a button to "Enable" the in-game free Commander Respecs.

Changes to the Penetration Mechanics

The armour-penetration capacity of HE shells of Tier VIII–X cruisers carrying 152–155 mm guns, which was previously calculated in accordance with the 1/6-calibre rule, will now be calculated following the 1/5-calibre rule.
The rules for calculating armour-penetration capacity have been changed for all HE and SAP shells: now the new rule "a shell penetrates armour if the armour-thickness value is less than or equal to the shell-penetration value" will be applied instead of the rule "a shell penetrates armour if the armour-thickness value is strictly less than the shell-penetration value." For example, 152 mm shells fired from Helena will be able to penetrate armour plating with a thickness of up to 25 mm, as opposed to the 24 mm it used to be.

These changes will allow cruisers to penetrate the armour of most same-tier ships without using the Inertia Fuse for HE Shells skill.

Changes to Cruiser and Battleship Armour protection
The changes to cruiser plating will make these ships more resistant to battleship salvos if they are positioned wisely: AP shells of certain calibres will ricochet off the plating of the central part of a cruiser if they impact at a sharp angle. At the same time, the central part of the hull and deck of cruisers carrying guns with a calibre of 190 mm or more now has thicker armour, while cruisers with guns of a smaller calibre have thicker armour only for the central part of their decks. These changes result in a greater distinction between light and heavy cruisers.
The armour thickness of Tier VI–VII battleships has been changed to preserve their ability to withstand shells fired from cruisers, taking into account the above-mentioned changes to the HE shell penetration rules.

Changes to the Inertia Fuse for HE Shells skill

The bonus applied to the armour-penetration capacity of HE shells now depends on the ship’s tier.
The skill will now reduce the chances of causing fire by half, instead of subtracting 1% or 3% from them, depending on the calibre.

It's only the standard chances of a fire being caused by HE shells which are reduced by half. Other bonuses to the chances of causing fire will function as before, such as the bonuses provided by the Victor Lima signal or the Demolition Expert skill.

This skill previously provided a significant advantage with minimum penalty, which made it too ultimate. The updated version of the skill brings it more in line with the efficiency of other skills. This will result in players exploring a wider variety of skill options for their cruiser and destroyer Commanders.

Table of changes to the penetration mechanics: