AFV Combat and Movement

This discussion was compiled by Tilman Walk from messages in a major thread on the SL Mailing List during February, 1999. Minor edits added by Alan Yngve, January 2002.

Tilman Walk:
Hi there, as I hate to loose something I learned already, I did a little compilation of what was discussed in the last couple'o days. Hope all citations are right. Keep on searching for the truth! (could tell, I should be a bibliotecar...)

SL AFV - Rules Basics, Armor and Speed

Tom Leete:
So the question becomes again - are we looking at the right thing? Could we model tank combat just as accurately by classifying all vehicles as light, medium, and heavy, ignoring the small differences? I think there are a lot of people who'd say we can.

Stan Rydzewsky:
I'm sure there are. A generic squad counter for all nationalities would probably be fine, too. There would just be side blue and side red, and generalized scenarios to represent various tactical situations. This sort of elimination of chrome probably really would make the game a better instructor of squad-level World War II tactics. OTOH it would also make it terribly dull, IMHO.

**** ARMOR ****

Tom Leete:
I agree with you completely - I wouldn't advocate that level of uniformity, either. But let me restate my question like this: When we are determining what factors to vary from nation to nation, unit to unit, are we looking at the right ones? Is it that important that one vehicle has +1 armor while another has +2? Did this really have an impact on the fighting over such a narrow grade? Certainly the difference between a +0 front armor on a T34 and the +3 on a Tiger is significant - as was the real difference in their respective armor protection. But could we classify targets as having armor types A, B, and C, with -2, +0, and +3 mods for each? Would this keep the level of 'realism' the same while dispensing with complexity? Or would this change not streamline a thing and make the game less 'colorful'?

As for armor factors, if anything, they understate the case. And they are supposed to take into account not only the armor thickness but its slope. When the JSIII appeared it scared the hell out of everybody because it could mount one big mother of a gun on a fairly mobile chassis, had a big turret, and was not overly heavy because its armor was so damn sloped. The Western Allied did go back to the drawing board once that thing was around.

Alain Chabot:
[and] As an aside, I think you are really underestimating the amount of work which went into cruching all the numbers and arrive at the values one finds on counters.

Tom Leete:
Actually I'm well aware of that. And I don't think I underestimate what went into those calculations at all. They might even take into consideration the percentage of area on a given facing that is sloped vs. vertical; soft spots where lucky hits could penetrate (or was this left out and purposefully added with the critical hit rule? Do we really need a critical hit rule?); tight corners that could effectivly 'trap' an incoming shell and were thus weak spots; average angle of target with respect to firer (i.e. they were rarely squarely face-to-face); change in impact angle due to distance of flight of the shell (which is travelling in a parabolic arc);

Alan Yngve:
Nope. For all practical purposes, most AT shots are very close to straight-line, due to the high muzzle velocity from the gun.

Tom Leete:
This was the Tobruk model of tank combat resolution. I followed it religiously for quite a while, generating Tobruk-like hit and penetration tables for various WWII vehicles so that I could extend the system to the Eastern and Western fronts - and took all those things I listed into consideration (to one extent or another). Finally I realized that in the long run, all of that stuff can just bleed into a single probability that you will kill the tank, which you might find doesn't vary so much from vehicle to vehicle _of the same category_ as all the mods and charts lead us to suspect. The variability inherent in what happens exactly when a rotating, plunging, deccelerating shell hits a tank on any one of a number of surfaces that can vary in thickness, slope, and angle to firer, not to mention the variability in the hardness of the armor or specific composition of the AP shell cap is such that all of this calculating involved in things like thickness, range, and velocity might not be so meaningful. And I dropped the game and all my work right then. Anybody want it? Beaten up copy of Tobruk, punched, with lots of extra home-made charts... even translated into inches for use with microarmor...

Ken Ives:
For the sake of illustration, let's consider a game system in which each side has five possible AFVs, with front armor modifiers of -2, -1, 0, +1, +2. Let's also assume that an armor modifier difference of 2 is important, while a difference of 1 isn't. Start by assuming side A has a +2, and B has a 0. You'd conclude that's important. Ok, now I model a different battle, where A has a +1 and B has a 0. You'd say that's unimportant, therefore an unnecessary complication. So let's eliminate the +1 category for simplicity, and make it a 0. It makes no significant difference. New scenario: A has the same AFV (formerly a +1, now a 0), but B now has a -1. See the problem? These AFVs HAD a difference of 2, which is significant, but with our elimination of the +1 armor category, the difference is now only 1, which isn't. Our simplification was acceptable when comparing the first two AFVs, but has caused the balance between two OTHER AFVs to go out of whack.

Alain Chabot:
In game terms, heavier armor (given the same gun) will translate in significantly different kill odds: a gun that needs an 8 to kill will do so on a 7 if the enemy has +1 armor, on a 6 if it has +2 armor and on a 5 if it has +3 armor. These odds are very different. Just try playing your infantry with a 5 ML instead of a 6. :)

Tom Leete:
I don't dispute that a +1 difference in armor mod can have a dramatic shift in kill probability. What my repeated question is, is this difference _in_game_terms_ justified by combat experience? Is the mechanism of the simulation valid? Is it needlessly complicated? This can be very much a matter of opinion on the part of the designer... or the gamer.

Alan Yngve:
I believe that the gamer desired the added detail. As for the game design, there are missing pieces from the "tank" portion of this game, even in ASL, but these can be traced back to the original premise of the game system an infantry model! Missing pieces? Crew quality/training, crew morale (as in breaking), command coordination ... but these lacks will not make me decide that I don't like to play this great game! :)

Alain Chabot:
If you read accounts of Kursk, you will see that one thing the Russkis did was maneuver close to the Germans thus negating the superior armor of the new Tigers and Panthers. The German tanks still killed the Russian ones on just about any hit, but at close range, the Russian gun now could kill the Germans on a fairly steady basis. In game terms this is translated by having range effect on penetration.

Tom Leete:
You are making just the points that I am (obliquely) driving at. Yes, the armor/deflection on a heavy (a categorization that speaks to level of protection, not gross tonnage) tank (say the Panther) was such that the armament on a medium tank (say the T-34 or M-4 Sherman) was at a real disadvantage. And by real, I mean that real tankers in combat changed their tactics to overcome this advantage - either they closed to point blank range or sought the flanks. So I would say that this is a difference that needs to be modeled in the game. Same with range effects on penetration - they influenced how the battle was fought, so they must be accounted for in the game. But what I am questioning is this: was there a qualitiative difference between various vehicles of the _same_ category such that they influenced combat and need to be included in the game? Was the T-34 routinely able to flank the PzIV on a small battlefield, so that we would be leaving something out by not giving it 33% more mobility?

PS - can you tell I'm working on my dissertation?

Greg Layton:
We also have to consider that the armor modifiers for the frontal armor and rear/side armor vary considerably, especially for the Germans. A tiger is more vulnerable from the side or rear than the front, so a less heavily armored and heavily gunned T34 could use it's superior speed and mobility to race around for a side shot. Even a BT or T70 might score a kill in this fashion, even though a frontal engagement would be suicidal. The Tiger has to consider these factors and try to minimize the chances of a shot. Seems that classifying armor types A, B and C would lose this important distinction, even though the basic SL and SL modules AFV Kill Tables do stipulate a better chance of kills for side/rear shots. And we can't forget about range effects on penetration, either. :-)

Dan Hannah:
PzKwIVF2 vs T34/76C, 1942, front armor, 7 hex range (300 - 350 yds), CE: 630/1296 pK vs 375 pK. This doesn't represent anything I've ever read

Tilman Walk:
I do not get the message. 630/1298 pK...375 pK....???????????????please decypher?

Dan Hannah:
Sure. pK = Probability of a kill. In the example: MkIV needs a 9 to hit, and a 7 to kill: 9 = 30/36 chance; 7 = 21/36 chance; for the probability of BOTH events happening (i.e., a "kill"), you multiply the numbers together, giving 630/1296.

T34/76C: 8 to hit and a 6 to kill: 25/36 * 15/36 = 375/1296. These odds are different than those obtained in SL, as I am using GI tables! Things get better at closer ranges, of course, and much deadlier:

MkIV: 33/36 * 25/36 (range 3 - 6) vs T34: 33/36 * 21/36 (Both also motionless, I forgot to mention).

The point being that the MkIVF2 was the FIRST upgunned German vehicle, yet it significantly outshines the T34, which, while not a super tank, was considered better than the MkIV until at least the next gun upgrade (ausfH), where they were considered comparable, by all of my sources.

The nice thing about these tables is it gives the Germans a fighting chance in Hill 621...

**** SPEED ****

Tom Leete:
Similarly, is the difference in mobility of a T34 (16 mf, IIRC) vs. a PzIV (12 mf) really that significant? The T34 may have been faster, or had better acceleration, or who knows what factor was used to arrive at these numbers, but in the heat of battle, does that difference really mean as much as the ability of the tank crews to react to the situation and decide where and when to move? Is crew efficiency reflected in these numbers? I can tell you now that your tanks could float and move 100 mph, but if the crew is green and doesn't know how to react, then I'll take a platoon of elite, slow, ground-bound vehicles any day. We are talking about a game here, and I know that, to me, the detailed rescension of vehicles in COI adds a lot of enjoyment to it. (So do the turret counters, but that's another story.) The tactics of the game are only part of its appeal to me.

I'll say again - I love COI. The turrets are indispensible. Otherwise you get players 'mock' firing their weapon at no target during a fire phase just so they can pivot the vehicle to face a newly arrived enemy on their flank... yeah, right.

Just prodding a little...

Alain Chabot:
Tom, in any kind of meeting engagement, it does make a difference if your tanks are 25% faster.

Tom Leete:
Let me refine my question a little: over the fairly tight battlegrounds that we play squad leader on, did this speed advantage make a real difference? I don't think we play any SL games on a board that is large enough to let armor do real maneuvering. Usually it's one to two moves a side before you're in contact. In scenario 5, for instance, a 3 board scenario, the Germans and Russians can be completely intermixed on the middle board in one move. So when you're starting that close, when you're playing on a field that is literally 1 1/2 moves in width and 2 moves in length, does that extra 33% of top speed really significiant? Not significant in game terms (I can tell you from personal experience that it is) but historically, did it change the way the tankers fought?

Alan Yngve:
Still lots of room for maneuver ... just because you enter engagement range does not mean that you should stop maneuvering! Albeit these will be tactical maneuvers as each side attempts to find favorable deployment sites. If the board is large enough for manover depends on a couple of things. What scenario are you discussing and what level of maneuver do you mean?

On the first point, far too many of our scenarios are not defined well enough to enable the AFVs to do any effective maneuvering, some early exceptions are #5 (Hill 621) and #14 (Paw of the Tiger). If there is insufficient space on the scenario board to offer a real reward to maneuvering vehicles ... for some strange reason we just don't see it! :)

On the second point. Most grand tactical doctrine in WW2 for armor stipulated that tanks were to _go_around_ enemy strong points. This was practiced repeatedly ... and can be found in many references. BUT it does not make a very exciting game at the company level! How many List members know that the US Sherman was (doctrinairally) NOT supposed to engage enemy armor(!) ... as this role was supposed to be solely the responsibility of the tank destroyer units. Admittedly it often did not work out this way, but that is more evidence of the constant tug between doctrine and the immediate needs of the line commanders. :)

OTOH, all nations who fought in WW2 discovered that their infantry was much more willing to fight (especially in the attack), if there was armor available to provide assistance ... this role is also often seen in our scenarios, but these AFVs are serving the "less exciting" role that was actually envisioned by the French for _their_ AFVs.

Stan Rydzewsky:
In regard to the movement allowance of the vehicles, I am much more in agreement with you (Tom), that the crew quality would have more of an effect than whatever "max. off road speed" figure they used to come up with the MP numbers. Still, I would argue that a good crew with a slightly faster vehicle could go further than the same crew with a slower vehicle. Hm, I guess I'm arguing now for crew quality modifiers to be applied to vehicle speeds, or perhaps using crew quality as the basis of the MP allowance with the vehicle type providing the modifier. (No, I'm not seriously arguing for this, but it *is* what occurs to me at this point.)

Now, more to the point, would the T-34 crew be aware of the slight edge in speed that they might have over a PzKw IV? No, probably not, so it would not affect their thinking or tactics. But the edge, if it exists, would still be there, and could have an effect on the outcome of an engagement even if the crew wasn't aware of it. So, if you want to teach tactics (i.e., present the players with the same choices the crew had) I agree, the game should ignore these differences. If you want to simulate "what really would have happened if..." I think the differences should be in there. I suppose I'm more in favor of the latter, and enjoy playing with a higher level of knowledge than the participants themselves may have had.

Alain Chabot:
Excuse me? What if? Good tactics is using your material to your advantage and try to negate the advantages of his material. Giving guys a tank that has inferior gun accuracy and inferior armor penetration and telling them to forget they have a faster machine is _not_ teaching them good tactics. There is nothing what if about the superior mobility of Russian tanks. The problem is in getting folks to play them properly. As in how they were historically used. A lot of the post-SL so-called chrome is involved in getting players to use their game pieces in ways which accurately reflect their actual utilization 50+ years ago. SL armor simply does a disservice to the German. COI is better. COD adds more accuracy. Each time you drive a pack of BT7 in circles around German Pz and manage to whack them by superior maneuver, you are doing something that never happened: BT7's were radioless and drove in platoons. Adding radioless AFV rules doesn't introduce a what if element, it removes one.

Tank design has always been a compromise between speed, hitting power, and armor. And range. And ammo stowage. Come on guys, we have French and British tanks in the system with _6_ MP, and the A11 (British) can't even use road movement and there are BT (that stands for _FAST_ tank, I guess the crew knew that beast was quick) doing 22 MP. Erasing speed differences between vehicles is not a serious option.

Tom Leete:
Nobody advocating erasing all speed differences - only removing ones that aren't significant in tactical terms under the conditions of battle portrayed - namely, small units of tanks in close contact. Once contact is established (and at this level, once it is established it is extremely difficult to withdraw) and the maneuvering is done, does the speed difference still matter? If yes, then keep it. If no, then throw it out. More importantly, is this difference in speed more or less important than the training or tactical doctrines of the crews? Can a faster tank with a 1-man turret compete with a slower one with a better 'head'? Better crews with better training have faster decision reaction times and get their vehicles into position to kill the enemy faster - is this more or less important that vehicle speed?

Alain Chabot:
BT7's were radioless and drove in platoons.

Tom Leete:
Hard to simulate a difference implemented at the platoon level when we're playing a game where the unit of maneuver is the individual vehicle... hence the need for restrictive rules.

Alan Yngve:
I would hope that folks who do early-war battles with armor would use things like the CoD radio-less AFV rules. They are there, hopefully they are used. But they are also almost "just" an extension of the armor tables within the rulebook.

Dan Hanah:
And as for running circles around German armor with BT7's, the radioless AFV rules in SL+ do not address this at all, they just randomly limit the number of AFVs that could move on a given turn. If I roll a 6 or a 5, I still can do not-so-ahistorical maneuvers. Read some accounts of Russian tank commanders. They did exactly that: run at top speed through a hail of shells to get point blank shots, shooting all the way in! I personally tend to do the same, if circumstances permit.

While I'm not going to get into the argument directly I'd like to direct anyone who is into this particular issue to refer to the references below. They are VERY important works and useful for understanding how to handle these sorts of questions.

Rude Mechanicals (& New Excalibar for WWI)
E.J. Smithers
ISBN 0-586-20305-2

Tank Warfare: A history of tanks in battle
Kenneth Macksey
ISBN 0-8128-1449-5

Numbers, Predictions, & War: The use of history to evaluate and predict the outcome of armed conflict
Col. T.N. Dupuy
ISBN n/a (and it was printed in 1976 and 1985, check used book stores)

Men against tanks: A history of anti-tank warfare
J. Weeks
ISBN n/a (printed in 1975)

Tank Killing: Anti-tank warfare by men and machines
I. Hogg
ISBN 1-885119-40-2

Future Wars: The worlds most dangerous flashpoints
Col. T.N. Dupuy
ISBN 0-446-36421-5

T.B. Allen
ISBN 0-425-11647-6

[1] Tank Warfare: A history of tanks in battle
K. Macksey
Chpt. 10 The Destruction of Poland