I'm confused about Combat Width and Reserves

[panda234]

I understand the 80 width restriction. I also understand there is a penalty for going over this width, but I'm not sure what it is. But my main issue is trying to determine optimum number of divisions (width) in a tile. If I don't have more than 80, who are presumably all fighting, where do my reserves come from? If I put in units for reserve, won't I get the penalty for more than 80 combat width?

My strategy so far is to have two tiles on my front line that can both access a tile on the defenders line and have them both attack, with one using an assisted attack so he doesn't move into the tile, then rinse and repeat. Then I can send my armor in through the hole. Should I be making the hole with my armor? But if I use armor on the tile with my defenders I'll be over the 80 width restriction.

 

[Kazakk]

You can put as many units as you wish as long as you don't get a supply penalty. You won't get the penalty if your templates are divisible by 80. For example, if there are 3 40w divisions attacking a tile, one will be on the reserve and you won't get a penalty. But, if there are 3 41w divisions attacking, one will be on the reserve and you will get a penalty for the extra 2w in the fight.
I wouldn't worry about placing optimal amount of divisions on places. Just place as many divisions as you can, and in case you lack enough divisions, use the terrain to your advantage (example: leaving only 1 division on mountains so you can reinforce other places in the front)

As for which division you should be using to attack, that depends on the situation. In an optimal scenario, you would have strong tank divisions with lots of soft attack and enough breakthrough, to quickly deorganize the enemy. But if you don't have the resources, you can use 40w inf/art divisions. If you can, you can leave motorized divisions to exploit a hole.
My attacking generals usually have 2-4 tank divisions with 4-8 motorized divisions, so that I can exploit a hole and go deep into the enemy territory without leaving holes of my own. I attack with the tank divisions and the motorized will just fill the gaps as I move forward.

 

[Harin]

Many of the answers you are seeking can be found in the Land Combat Wiki Page. On the page, press Ctrl-F to bring up the search window, type Penalty, and you will find quit a few answers.

More specifically, the "stacking penalty for having too many divisions in combat: (-2% per division over the stacking limit. The stacking limit is 8, plus 4 per flanking direction" means that in your case of two tiles attacking one defending tile makes for a 12 division stacking limit, before receiving a penalty.

Each battle has a specific combat width determined by how many tiles the attacker attacks from. The first tile gives 80 combat width, while all others add 40 combat width each. In your example of attacking from two tiles, that gives you a combat width of 120.

No matter how many divisions you commit to the attack, only the first divisions that can fill the 120 combat width would initially engage. All the other divisions you committed are in reserve. As your attacking divisions run out of organization, they stop attacking, fall out of combat, and are replaced with a division in reserve. How fast the reserve unit joins the fight has a base chance of 2% per hour, or about an average of 35 hours to engage. Researching radios greatly decreases that 35 hour window.

I do recommend attacking with your armor. That way, once a break has been achieved the armor will have gained movement during the battle and advance much quicker into the tile. There is wasted time if you wait for the break and then advance the armor.

 

[Mousetick]

- The first attack direction is limited to 80 width. Each additional attack direction, from adjacent tiles, whether attack-move or attack-don't-move doesn't matter, increases the width limit by 40. So attack from 1 tile: 80 max width. From 2 tiles: 120 max width. From 3 tiles: 160 max width.
- Only divisions actively fighting in the attack contribute to the combat width. Other divisions that are part of the attack order, but in reserve, waiting as reinforcement, do not contribute to the combat width. Other divisions located in the same tile, but not part of the attack order, do not contribute either. For example, you have 10 divisions, each 20-width, in one tile. You order 6 of them to attack another tile. 4 of the 6 will be fighting, while the other 2 will wait in reserve. Total width: 80. The remaining 4 divisions in the tile are not involved - they can be given a different order, or defend, while the first attack is taking place.
- Generally you should be making the hole with your armor, since it's good for that, as long as the terrain is favorable.

If you want to avoid the penalty caused by exceeding the combat width, without having to worry about it in any situation, only create/use division templates which width is 10, 20 or 40.

Also Harin above rightly mentions the stacking penalty, which is separate from the combat width penalty.

More info about combat width and reserves on the Wiki: Land battle