SAWE/MILES II and pKs

[kbluck]

Looking at the pK tables, I've always thought the pKs for tanks from the sides and rear were way too low. So, I went to the MILES tables to try and figure out how they were derived. I now think I understand how you came up with them, and I also have what I think is a good reason to argue that the game's values really are way too low for side and rear shots.

Taking the M1A1 as an example, it seems that generally you added about 10% to the "catastrophic kill" chance for a given weapon at a given angle. However, I couldn't help but notice that in MILES, there are multiple types of kill, and many of those chances are substantially higher than for catastrophic.

I interpret "catastrophic" to mean the vehicle is burning or explodes, and the crew is probably dead. "Mobility" means the suspension is too damaged to move or the engine is dead, or perhaps the fuel is lost. "Firepower" means most likely the ammunition blew up, which is often not catastrophic for the M1 due to the blowouts, or might also mean damage to the weapon or targeting systems. Lastly, there's commo, which probably is outside the scope of the game.

To give an example, an M1A1 being shot from the rear by a 125mm is listed as having a catastrophic kill chance of 30% in MILES and 40% in ATF. Now, I always thought that 40% was too low, and now I know why: in the game, the system escapes unscathed if there is no catastrophic kill. In MILES, however, the vehicle also has a 75% chance of a FP kill and a 90% chance of a mobility kill from the same hit.

Now, perhaps I'm misunderstanding how to use these tables, but my impression is that all of these kill factors are concurrent. That is to say, you check all four whenever a vehicle is hit. Assuming that's true, it seems to me that a coincidence of FP and MOB kills is the same thing as a catastrophic kill for game purposes, since the game doesn't track the fate of the crew as they would at NTC. If a vehicle can neither move nor fire, isn't that as good as dead for game purposes?

So, in the scenario above, there is a 68% chance of both FP and mobility kill occurring. Add that on to the 30% catastrophic kill chance, and eliminate the double-counting for catastrophic kill (since that state implies both FP and MOB as well) and you have an overall chance of 77% for a "game kill", nearly twice the database1 pK value.

If you add on the chance of either an FP or MOB kill, then the odds of the tank suffering significant damage that will greatly impair its function is even higher, > 95%. But unfortunately the game doesn't track system damage.

Have I misunderstood how MILES works? Are there factors I haven't considered?

--- Kevin

[Scully]

Hey Kbluck,

Where do you get the MILES lists/tables from? Are they part of the ATF Database or somewhere else?

Thanks,
Brian

[kbluck]

NTC Handbook 98-1 has some tables in its appendices and is available online at:

http://call.army.mil/products/handbook/98-1/tble.htm

--- Kevin

[Pat Proctor]

The way I understand these tables is that one die roll is done. If it is below the commo kill number, commo goes out. If it is below the commo kill AND the weapon kill number, the weapon goes out. If it is below commo, weapon, and mobility pK, the mobility goes out. And, if it is below the catastrophic kill number, the vehicle is killed.

We simply used the catastrophic kill numbers (though we had a lot less thorough source, per vehicle than the data you are using here) to determine pK's.

[kbluck]

The way I understand these tables is that one die roll is done. If it is below the commo kill number, commo goes out. If it is below the commo kill AND the weapon kill number, the weapon goes out. If it is below commo, weapon, and mobility pK, the mobility goes out. And, if it is below the catastrophic kill number, the vehicle is killed.

I considered resolution alternatives similar to that, but they seemed kind of weird. I mean, really, are the weapon and mobility systems really that interdependent? I certainly hope combat vehicles aren't designed that way.

Under the one-roll scheme you describe, it would be impossible to obtain a FP kill without also obtaining an MOB kill. That seems kind of silly. Why would a non-catastrophic turret hit affect the mobility? And vice versa for the hull. If the engine block is cracked open, how does that affect the gun directly? Don't they have backup hydraulics/power? Etc.

If you meant that they are exclusive, that is to say 1-30 CAT, 31-75 FP, 76-90 MOB, then how do we interpret tables where different kills have the same chance? And now, its impossible to get both FP and MOB kills with the same hit, which seems equally unlikely.

Look at the M1A1 hit front for the AT-3 Sagger. The FP kill is *lower* than the catastrophic kill. Many other tables have sub-pKs lower than or equal to the CAT kill. How do you resolve *that* with one die roll? It just doesn't make sense that way.

The sub-pK chances seem reasonable to me as independent rolls. If an M1 gets hit in the butt and armor penetrated, the first thing that round is probably going to encounter is the engine, hence 90% MOB kill. If the round has the steam to continue, it might also hit the ammo. Hence, somewhat lower 75% chance of FP kill.

Surely, the contractors that came up with these protocols would have considered such issues.

--- Kevin