In detail, what Sigma Armor does is compute the difference D=600-(base stat total). The difference D is then split into portions, the size of which depends on how big D is. These portions are then added to the Pokémon's base stats: first portion to the lowest stat, second to the second lowest etc.

The portions are divided like this:

**Step 1:**

Divide D by 2 and round it up. This gives you the maximum portion size M.

If M is under 50, raise it to 50. The increase must be significant.

If M is above 100, reduce it to 100 to 90. The increase mustn't be ridiculously too much, *which is why it was nerfed to 90*. This was done to avoid stats of 150 in weak Pokémon (for non-Legendaries and non-Mega Evolutions, anything beyond 130 is absurdly powerful) and to make the 3rd adding portion substantial.

**Step 2:**

Starting from the lowest base stat, excluding HP, add M points to it (or all you have left if there are less than M left) and subtract them from D.

If there are several equally low stats, they split all portions one of them would get equally.

Once you empty D, you are done.

After this procedure, the starting Pokémon has a BST of 600 reached by boosting its lowest stats. The idea was that 2 weakest stats are boosted, and the portion sizes were set accordingly. For very weak Pokémon (here defined as having a BST under 400), more than 2 are boosted.

Let me illustrate what I mean with a few examples.

**Example 1:**

**Torterra**, with stats distributed as 95/109/105/75/85/56 and a BST of 525, has a difference D=600-525=75.

Step 1: 75/2 rounded up is 38<50, so maximal portion M=50.

Step 2: Our portions are then 50 and 25. Torterra's lowest stat, Speed, gets the 50, and its second lowest stat, Special Attack, gets the 25.

In the end we have Armoured Torterra with stats 95/109/105/**100**/85/**106** and BST 600.

**Example 2:**

*Ledian*, with stats 55/35/50/55/110/85 and a BST of 390, has a difference D=600-390=210.

Step1: 210/2=110>100, so M=90.

Step 2: Our portions are 90, 90 and 30, added in that order to the weakest stats Attack, Defense and Special Attack.

In the end we have Armoured Ledian with stats 55/**125**/**140**/**85**/110/85 and BST 600.

Ledian of all things now hits like a truck and is amazingly durable.

**Example 3 (the ultimate test):**

**Solo Form Wishiwashi**, with stats 45/20/20/25/25/40 and the lowest BST of all Pokémon at 175, has a difference D=600-175=425.

Step 1: 425/2>100 so M=90.

Step 2: Our portions are 90, 90, 90, 90, 65. All available stats are increased.

In the end we have the horror that is Armoured Wishiwashi with stats 45/**110/110/115/115/105**, only slightly weaker than School Form Wishiwashi, but three times as fast.

EDIT: changed upper bound for portion size if there are more than 2 portions to 90