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Square root attrition model

Posted: Fri Aug 23, 2024 6:13 am
by yiyuezhuo
It is intriguing to compare the combat resolution systems in TOAW and PZC, particularly noting that both games share some fundamental concepts, such as victory conditions driven by morale checks. However, a notable difference lies in how losses are calculated for the target units:

In PZC, the target's losses are directly proportional to the attacker's assault value:

target loss ratio = k * attacker's assault value / target defense value

Contrastingly, in TOAW, the attrition value, based on information scattered across the internet, is proportional to the square root of the attacker's attrition value (which is the sum of their AP or AT values):

target loss ratio = k * sqrt(attacker's AP or AT value) / sqrt(target defense value)

When the attacker is sufficiently powerful, the square root function in TOAW's attrition model resembles the maximum attacker mechanism in DC, which reduces the attacker's strength after multiple attacks within a single combat round. This can be represented as a piecewise function with both linear and logarithmic components:

loss ratio = k * attacker's fire value (linear if the threshold is not reached)
loss ratio = k * thresholded attacker's fire value + k2 * log(extra attacker's fire value)

Regarding defense values, consider the effect of bombardment. Doubling the strength results in approximately a 2 * 1/sqrt(2) = sqrt(2) ~=1.41 losses increase, assuming no stacking limit penalties apply (in PZC, a linear relationship would prevent such a increase (2 * 1/2 = 1)). It looks that TOAW just assumes the target units are uniformly distributed within the combat zone and that artillery fire strikes randomly across the area. :roll:

Re: Square root attrition model

Posted: Fri Aug 23, 2024 9:51 am
by Lobster
yiyuezhuo wrote: Fri Aug 23, 2024 6:13 am It looks that TOAW just assumes the target units are uniformly distributed within the combat zone and that artillery fire strikes randomly across the area. :roll:
Unguided artillery does strike randomly. Not like it's a direct fire weapon.

"For example, a 25 pounder needs to land 8 – 32 shells per hour for neutralisation (for about 10% casualties; Global Security Organisation, n.d.), but 600 shells in a 100 x 100 yard sector are required to militarily ‘destroy’ the target (meaning 30% casualties)."

https://balagan.info/artillery-and-mort ... ics-of-ww2

Re: Square root attrition model

Posted: Fri Aug 23, 2024 11:35 pm
by rhinobones
yiyuezhuo wrote: Fri Aug 23, 2024 6:13 am Contrastingly, in TOAW, the attrition value, based on information scattered across the internet, is proportional to the square root of the attacker's attrition value (which is the sum of their AP or AT values):
target loss ratio = k * sqrt(attacker's AP or AT value) / sqrt(target defense value)

You seem to know a bit about internal TOAW calculations, do you have access to the TOAW code? If not, where on the internet are you getting your information?

Re: Square root attrition model

Posted: Sat Aug 24, 2024 12:03 am
by yiyuezhuo
rhinobones wrote: Fri Aug 23, 2024 11:35 pm
yiyuezhuo wrote: Fri Aug 23, 2024 6:13 am Contrastingly, in TOAW, the attrition value, based on information scattered across the internet, is proportional to the square root of the attacker's attrition value (which is the sum of their AP or AT values):
target loss ratio = k * sqrt(attacker's AP or AT value) / sqrt(target defense value)

You seem to know a bit about internal TOAW calculations, do you have access to the TOAW code? If not, where on the internet are you getting your information?
Sources:
https://www.matrixgames.com/forums/view ... p?t=319298
https://steamcommunity.com/sharedfiles/ ... 1544712899

Re: Square root attrition model

Posted: Sat Aug 24, 2024 12:23 am
by Curtis Lemay
Diminishing returns.

Re: Square root attrition model

Posted: Sat Aug 24, 2024 5:46 pm
by cathar1244
@yiyuezhuo

Something to consider is that TOAW combat resolution has to handle a wide spread of possible time and space combinations in a scenario.

That said, the engine gives a result. It is up to scenario designers to set the attrition divider such that losses look somewhat realistic for the space and time scales involved.

Interesting thread topic.

Cheers

Re: Square root attrition model

Posted: Fri Aug 30, 2024 1:55 am
by yiyuezhuo
Curtis Lemay wrote: Sat Aug 24, 2024 12:23 am Diminishing returns.
The new naval combat system seems to lack a similar "diminishing marginal returns" mechanism; I wonder where the boundary lies.

Re: Square root attrition model

Posted: Fri Aug 30, 2024 2:02 am
by yiyuezhuo
cathar1244 wrote: Sat Aug 24, 2024 5:46 pm @yiyuezhuo

Something to consider is that TOAW combat resolution has to handle a wide spread of possible time and space combinations in a scenario.

That said, the engine gives a result. It is up to scenario designers to set the attrition divider such that losses look somewhat realistic for the space and time scales involved.

Interesting thread topic.

Cheers
The attrition divider is included in the constant k, and the square root method (similar to a variant of Lanchester's linear law: dx/dt = -k * sqrt(xy)) makes it fundamentally different from PZC's linear method (following Lanchester's square law: dx/dt = -k * y). What I mean is, for the same battle, one of them must be better than the other.

Re: Square root attrition model

Posted: Fri Aug 30, 2024 2:14 am
by Curtis Lemay
yiyuezhuo wrote: Fri Aug 30, 2024 1:55 am
Curtis Lemay wrote: Sat Aug 24, 2024 12:23 am Diminishing returns.
The new naval combat system seems to lack a similar "diminishing marginal returns" mechanism; I wonder where the boundary lies.
Ships can't dig in or hide.

Re: Square root attrition model

Posted: Fri Aug 30, 2024 1:17 pm
by cathar1244
yiyuezhuo wrote: Fri Aug 30, 2024 2:02 am
cathar1244 wrote: Sat Aug 24, 2024 5:46 pm @yiyuezhuo

Something to consider is that TOAW combat resolution has to handle a wide spread of possible time and space combinations in a scenario.

That said, the engine gives a result. It is up to scenario designers to set the attrition divider such that losses look somewhat realistic for the space and time scales involved.

Interesting thread topic.

Cheers
The attrition divider is included in the constant k, and the square root method (similar to a variant of Lanchester's linear law: dx/dt = -k * sqrt(xy)) makes it fundamentally different from PZC's linear method (following Lanchester's square law: dx/dt = -k * y). What I mean is, for the same battle, one of them must be better than the other.
For any particular battle, one of the systems probably offers a more realistic outcome.

One would have to test a series of battles over both systems with identical parameters. It might then be possible to state which system produces better results more often.

The attrition divider and replacement rates are key variables to control the ability of units to remain effective in TOAW. The designer of a scenario has to test various settings of these parameters to see if outcomes resembling history take place.

There is another part of these systems and that are the databases that define the equipment of the units. An interesting comparison between the two games would be to see how they rate the same pieces of equipment.

Cheers