A Quick Battle AAR: Shermans vs Pz IVs, Not Your Fathers Combat Mission

[scottie]

In CMx1 at least, you could knock out a tank without knowing it. The hit text would just say "Penetration". It is only when your guys know for sure that the shots resulted in a KO that the "Knocked out" text would appear.

sorry yip understood thanks. (read it wrong first time)

[Battlefront.com]

Quality vs. Quantity is always an interesting thing to ponder. The pro of Quality is that in a really tight situation it can make the difference between walking away victorious or at least walking away. The con is that you have fewer eggs in your basket, so if the panicky Green gunner on the other side gets a lucky hit on your Crack crewed tank... well, it's more likely going to hurt.

The pro of Quantity is that you can cover more options with more assets in more ways at more times than you could if you had fewer. This is especially important in armored warfare because if you can get on two or more sides of an enemy tank you have a much better chance of knocking it out and surviving. The con, of course, is that you could do everything really well tactically and still wind up coming up short if the other guy has better Quality.

And there is the rub. If you go into a battle knowing that the enemy has poor quality equipment and crews, then going with fewer high quality equipment and crews might do wonders for you. But if you find the map to be closed in and infantry is now king of the battlefield... you might have been better off with more stuff with lower quality.

So much to ponder

Steve

[Stitch]

For every comment Steve makes, five snarky replies must be made.

I think Steve is inferring that there was really a 4:1 ratio of Sherman to Panther deaths. This is because the Panther is better armoured when compared to the little pkw IV (I loved the F2 variants in ASL!) and could withstand 4 direct hits, and therefore fire 4 times more than 1 Sherman.

/joke.

Okay, how 'bout a 4.5 ratio ETO wide?

[Bil Hardenberger]

In this battle I don't think the crew quality made that much difference. At sub 500m ranges like here, even a regular gunner should hit a non moving target most times. I think we are seeing that in this game.. Warren has hit with his regular crews with almost every round he has fired... I have missed a few, but only when firing against a moving target.

Crew quality might make a difference in spotting and reloading speeds though.

In this game against Warren's Sherman Platoon moving up AA3 I have three tanks, two crack and one elite... 2nd Platoon when it comes on line will have two veteran and two regular crews. What's going to be your excuse on that side Warren if your force falls apart?

[Rocky Balboa]

2nd Platoon when it comes on line will have two veteran and two regular crews. What's going to be your excuse on that side Warren if your force falls apart?

Oh boy, Hanz is talking smack, see this is what I like to hear. What say you Joe?

[The_Capt]

In this battle I don't think the crew quality made that much difference. At sub 500m ranges like here, even a regular gunner should hit a non moving target most times. I think we are seeing that in this game.. Warren has hit with his regular crews with almost every round he has fired... I have missed a few, but only when firing against a moving target.

Crew quality might make a difference in spotting and reloading speeds though.

In this game against Warren's Sherman Platoon moving up AA3 I have three tanks, two crack and one elite... 2nd Platoon when it comes on line will have two veteran and two regular crews. What's going to be your excuse on that side Warren if your force falls apart?

Heh, how about I was outnumbered 8 to 12 going in? And tank-wise 5 to 12..I think that'll do nicely.

Crew quality does matter in the spot-target-shot loop. Regular crews average 12-14 seconds while Crack-Elite average about 8 seconds. So regular crews get shots off a lot quicker. The also tend to spot better and of course don't get rattled or bail as easily.

Tough call on quantity versus quality. I try not to invest too much in any "wonder teams". Say Panthers with Elite crews, the battlefield is way to chaotic and if you invest that many points in one place you really take a hit if you lose em.

For those keeping score I am way up at this point considering I am taking out Elite-Crack crews with dog-faced regular GIs in humble Shermans.

[Battlefront.com]

I think most of us would rather have a better vehicle with a Regular crew than a poorer vehicle with an awesome crew. A great crew can only do so much, as Bil is finding out.

Think of an extreme, like Crack crewed Stuarts vs. Green crewed Tiger IIs. In a head to head match there's no contest. Even under optimal circumstances the Stuarts would be lucky to immobilize a Tiger II, while a Stuart in the crosshairs of a Tiger II stands almost no chance of surviving.

Steve

[LC-]

Steve I think you are exactly right there obviously, but one question has come to my mind as a result of the quality/quantity debate. Since quantity is one of the reasons for allied victory in the war, and quality (mid war) was one way the germans were able to hold on for so long, doesnt it make unit experience more of a strategic element? I guess what i mean is that since each forces unit tactics arent represented is unit experience from regular to crack needed?

By the way Im in no way asking for change, just something that crossed my mind.

[Rocky Balboa]

It may not be needed and players can decide before hand that only regular crews will be allowed in an upcoming QB. Likewise scenario designers can chose to use these options or not.

For a game that encourages and thrives off of player made content, the more options the players have, the happier we are.

[LC-]

Very true Rocky!

[Fredrock1957]

Don't forget another key factor for a crew and there are 7 levels in CM:SF is the Motivation Factor... This can assist in troops sticking to their orders and going beyond the call... So as a designer between Equipment, Crew Experience, and Movtivation you can create many different combinations of talent for the commander to use...

[Battlefront.com]

Since quantity is one of the reasons for allied victory in the war, and quality (mid war) was one way the germans were able to hold on for so long, doesnt it make unit experience more of a strategic element?

Sure, but that doesn't mean it wasn't also a factor at the tactical level. Or think about it this way... how could it possible effect the strategic level if it had no impact on the tactical level?

One of the very interesting things about tactical combat, which I didn't really appreciate until CMBO, is how small variables can have quite big outcomes. Before CMBO I was largely a strategic level wargamer. At that level a couple of "bad rolls" don't usually have much of an effect. But at the tactical level, a gunner who can load 5 seconds faster than his opponent can change the entire outcome of that tactical battle with one shot. Or not, it depends completely on the situation.

Steve

[Vark]

Can you have, or would it be possible to give different crew members different ratings? So you might have a crack commander (veteran from many a campaign) a green driver (hasty replacement for an injured crew member) and an average gunner (joined unit two weeks ago, still finding his feet). You might even have a random pick option where the crew costs less than a crew with the same uniform experience. I remember CM1 games where you would buy an average tank platoon but get a mix of experience. Again, another choice/gamble to make, another unknown quantity facing your opponent and vice versa.

[Battlefront.com]

No, we don't go down to that level of detail. What happens is Experience is averaged downward.

Steve

[LongLeftFlank]

One important factor relating to crew training, experience and leadership is that (depending on the situation) a higher quality force may be able to get to the field of battle (the scenario) in better shape / earlier, and most important, take up better positions once there. As Sun Tzu says, the wise leader chooses the time and place (not always possible in practice of course for countless reasons, mainly FOW).

The scenario designer can reflect some of that with judicious/clumsy force placement; the experienced player can do it too (even with Green forces) by wisely using his setup zones. Come to think of it, that ought to be in the "Scenario design manual" -- the less experienced the player's force, the less latitude the designer should give him in terms of initial setup options/space.

[Peregrine]

One of the very interesting things about tactical combat, which I didn't really appreciate until CMBO, is how small variables can have quite big outcomes. Before CMBO I was largely a strategic level wargamer. At that level a couple of "bad rolls" don't usually have much of an effect. But at the tactical level, a gunner who can load 5 seconds faster than his opponent can change the entire outcome of that tactical battle with one shot. Or not, it depends completely on the situation.

Steve

This is one of the reasons I preferred large scenarios under the old system. A piece of luck with AT/tank gunnery could have big impact on the result of little scenarios.

Big scenarios however with lots more hit calculations the luck would balance out across both players.

Hopefully with the randomness of hit calculations taken out little scenarios should be more fun and playable.

The best way to get a balanced battle I felt would be a 3000 point (? I think this is the amount, haven't PBEMed for a couple of years, may have been 5000) meeting engagement. It grated a little bit this was also unrealistic and big meeting engagements like this never happened in the way portrayed in CM.

[Txema]

Originally Posted by Charles

All else being equal, a group of M4A3 Shermans should have a modest advantage head-to-head at 300m against an equal-sized group of PzIVH.

Here is why. While the German 75mm gun is better than the US 75mm, the Sherman has superior frontal armor. The PzIVH has an obsolete turret front and virtually no armor sloping anywhere. Further, its frontal armor is face-hardened which is a liability against the capped armor-piercing ammunition (APCBC) used by the western Allies in 1944.

Let's first examine the PzIVH shooting at the M4A3 Sherman straight on, non oblique hits:

M4A3 Sherman frontal armor:

76mm @ 30° turret (treated as 69mm due to mediocre armor manufacturing quality)

89mm @ 0° gun mantlet (treated as 80mm)

51mm @ 56° upper hull (treated as 46mm)

51mm @ 15°(avg) lower hull (treated as 46mm)

German PzIVH (75mm KwK40 L/48) armor penetration (average) at 300m at various armor slopes:

0°: 127mm

15°: 120mm

30°: 99mm

56°: 53mm

Hit results:

M4A3 Sherman turret: easily penetrates (120mm vs 69mm)

M4A3 Sherman gun mantlet: easily penetrates (127mm vs 80mm)

M4A3 Sherman upper hull: usually but not always penetrates; majority of killing energy absorbed by armor (53mm vs 46mm)

M4A3 Sherman lower hull: easily penetrates (120mm vs 46mm)

Summary:

If the Sherman is hit straight on in the turret or lower hull it's in bad shape, but if it's hit in the upper hull (aka glacis plate) it has a decent chance to survive. Not great, but decent. And the glacis plate is the largest and most central of the potential target areas so many hits will occur there.

Now let's examine the M4A3 Sherman shooting at the PzIVH straight on, non oblique hits:

PzIVH-late frontal armor (all face-hardened, which is a liability versus US APCBC shells -- this is very important!):

50mm @ 10° turret

80mm @ 10° upper hull

80mm @ 15° lower hull

M4A3 Sherman (75mm M3 L/40, firing APCBC) armor penetration versus face-hardened armor (average) at 300m at various armor slopes:

10°: 96mm

15°: 93mm

Hit results:

PzIVH-late turret: easily penetrates (96mm vs 50mm)

PzIVH-late upper hull: penetrates, some killing energy absorbed by armor (96mm vs 80mm)

PzIVH-late lower hull: penetrates, some killing energy absorbed by armor (93mm vs 80mm)

Summary:

PzIVH armor cannot withstand a straight on hit from a Sherman anywhere. Its best hope is for a hull hit where some of the energy is absorbed, but often this won't be enough to save the tank.

When oblique angles are taken into effect the picture changes. The more the shot deviates from a straight on hit the greater the chance of deflection instead of penetration. Sloped and rounded armor enhances this chance more so than vertically aligned plates. If the chance of a penetration from straight on is marginal, then a less optimal angle of impact likely means the round does not penetrate. When examining the numbers above, it's pretty clear that the Sherman is far more likely to survive a hit from a PzIV than the PzIV is to survive a hit from a Sherman.

…there are some really deeply entrenched assumptions about what German (and American) equipment should and should not be capable of. And yet when we dig down a little, it seems that these hardened assumptions are not based on anything real.

The above is a perfect example. The assumption is that PzIV = Sherman. Case closed?

Well, the assumption is wrong. These two tanks are not quite equivalent. They have significantly different strengths and weaknesses. In some situations I'd want a PzIV, and in others a Sherman. And at 300m head to head, give me the M4A3 please. The armor on the PzIV is obsolete by 1944. Even to American guns, it just can't hold up, and Combat Mission reflects this.

First of all, thank you very much for all these detailed explanations. I really appreciate them !!

However, there is something that I am not understanding properly: when you speak about the hit results on the M4A3 Sherman, you state that:

“M4A3 Sherman upper hull: usually but not always penetrates; majority of killing energy absorbed by armor (53mm vs 46mm)”.

And later you also state referring again to the Sherman

“If the chance of a penetration from straight on is marginal, then a less optimal angle of impact likely means the round does not penetrate.”

But the chance of penetration should be quite high. 53mm vs 46mm should mean that most of the times the shell should penetrate. (53/46 = 1.15, penetration capability is 15% larger than the thickness of the plate). Then why do you speak about marginal chance of penetration? I think that in this case we have a high chance of penetration… and consequently if the Panzer IV hits the M4A3 Sherman three times with this high chance of penetration, it must be very unlucky not to penetrate it at least once. Not to achieve a penetration with 3 hits is possible, of course, but it is a very unlucky result for the Panzer IV.

Moreover, although the majority of killing kinetic energy would be absorbed by armor in case of penetration, the AP rounds used by the Panzer IV have an explosive filling to increase the destruction after penetration and therefore they should be able to produce important damage to the M4A3 Sherman.

Battlefront, could you please comment on these?

P.S. BTW, the ratios for the M4A3 Sherman hitting the Panzer IV at the upper hull and lower hull are quite similar: 96mm vs 80mm -> 96/80 = 1.20 (penetration capability 20% larger than the thickness of the plate) and 93mm vs 80mm -> 93/80 =1.16 (penetration capability 16% larger than the thickness of the plate) and in both cases you state that there will be a penetration.

[GhostRider3/3]

No, we don't go down to that level of detail. What happens is Experience is averaged downward.

Steve

Good to know, besides most crews unless promoted, or injured stuck pretty much together.

[SD Smack]

Originally Posted by Battlefront.com No, we don't go down to that level of detail. What happens is Experience is averaged downward.

Steve

Good to know, besides most crews unless promoted, or injured stuck pretty much together.

Plus having a strong leader (tank commander in this case) would trickle down to the crew. So if the TC is crack then I would degrade the crew to veteran or maybe regular if the entire crew minus the TC is green....but never underestimate the affect of a strong leader in these positions...they teach and inspired their subordinates to do more than they would prpbably do otherwise.

Steve-o

[GhostRider3/3]

First of all, thank you very much for all these detailed explanations. I really appreciate them !!

However, there is something that I am not understanding properly: when you speak about the hit results on the M4A3 Sherman, you state that:

“M4A3 Sherman upper hull: usually but not always penetrates; majority of killing energy absorbed by armor (53mm vs 46mm)”.

And later you also state referring again to the Sherman

“If the chance of a penetration from straight on is marginal, then a less optimal angle of impact likely means the round does not penetrate.”

But the chance of penetration should be quite high. 53mm vs 46mm should mean that most of the times the shell should penetrate. (53/46 = 1.15, penetration capability is 15% larger than the thickness of the plate). Then why do you speak about marginal chance of penetration? I think that in this case we have a high chance of penetration… and consequently if the Panzer IV hits the M4A3 Sherman three times with this high chance of penetration, it must be very unlucky not to penetrate it at least once. Not to achieve a penetration with 3 hits is possible, of course, but it is a very unlucky result for the Panzer IV.

Moreover, although the majority of killing kinetic energy would be absorbed by armor in case of penetration, the AP rounds used by the Panzer IV have an explosive filling to increase the destruction after penetration and therefore they should be able to produce important damage to the M4A3 Sherman.

Battlefront, could you please comment on these?

P.S. BTW, the ratios for the M4A3 Sherman hitting the Panzer IV at the upper hull and lower hull are quite similar: 96mm vs 80mm -> 96/80 = 1.20 (penetration capability 20% larger than the thickness of the plate) and 93mm vs 80mm -> 93/80 =1.16 (penetration capability 16% larger than the thickness of the plate) and in both cases you state that there will be a penetration.

I also am not understanding this as well, as I am more of an overall Historian and rely more on facts then formulas. All I know is the 75mm L/48 can pretty much easily penetrate 96mm at 500m or less. I was just more or soo looking for a answer as to why... deflection? It just seems that it would have out of 3 shots at 500m or less at least a 30% chance of penetrating, but when all 3 did not, I was curious.

Later there was a hit from the front at around 450m I think... I still can not wait to see the results but am a little concerend sort of that if the 75mm L48 can penetrate up to 96mm of armor... what ammo were they using? HE?

[GhostRider3/3]

Plus having a strong leader (tank commander in this case) would trickle down to the crew. So if the TC is crack then I would degrade the crew to veteran or maybe regular if the entire crew minus the TC is green....but never underestimate the affect of a strong leader in these positions...they teach and inspired their subordinates to do more than they would prpbably do otherwise.

Steve-o

Yes if you look at the adventure of Michael Whittmen and Bobby Woll it was truly a great combination. Bobby was extremely proficient with his gunnery skills, and Michael with his decision and reaction capability. In the end it is teamwork... that makes a tank and its crew act as one.

[zukkov]

mentioning wittmann reminds me of my first battle in cmbo. knowing absolutely nothing about the game(my friend was showing me how to issue orders, etc), i totally wiped the floor with wittmann and his team, crushing the british. all attempts after that, when i supposedly knew what i was doing, ended in disaster.

[ShakyJake]

First of all, thank you very much for all these detailed explanations. I really appreciate them !!

However, there is something that I am not understanding properly: when you speak about the hit results on the M4A3 Sherman, you state that:

“M4A3 Sherman upper hull: usually but not always penetrates; majority of killing energy absorbed by armor (53mm vs 46mm)”.

And later you also state referring again to the Sherman

“If the chance of a penetration from straight on is marginal, then a less optimal angle of impact likely means the round does not penetrate.”

But the chance of penetration should be quite high. 53mm vs 46mm should mean that most of the times the shell should penetrate. (53/46 = 1.15, penetration capability is 15% larger than the thickness of the plate). Then why do you speak about marginal chance of penetration? I think that in this case we have a high chance of penetration… and consequently if the Panzer IV hits the M4A3 Sherman three times with this high chance of penetration, it must be very unlucky not to penetrate it at least once. Not to achieve a penetration with 3 hits is possible, of course, but it is a very unlucky result for the Panzer IV.

Moreover, although the majority of killing kinetic energy would be absorbed by armor in case of penetration, the AP rounds used by the Panzer IV have an explosive filling to increase the destruction after penetration and therefore they should be able to produce important damage to the M4A3 Sherman.

Battlefront, could you please comment on these?

P.S. BTW, the ratios for the M4A3 Sherman hitting the Panzer IV at the upper hull and lower hull are quite similar: 96mm vs 80mm -> 96/80 = 1.20 (penetration capability 20% larger than the thickness of the plate) and 93mm vs 80mm -> 93/80 =1.16 (penetration capability 16% larger than the thickness of the plate) and in both cases you state that there will be a penetration.

I think you might be misunderstanding the way he's using the term "marginal" here, Txema. Having a marginal advantage in penetration here means that there is slightly over a 50% chance of penetration, since the penetration value for the projectile is an average of the upper and lower range it can fall between. So, under an ideal circumstance of being directly head on to the target and at that range, it will probably penetrate, just as he has said. However, once any kind of imperfect conditions start creeping into the equation, things start to become more iffy.

Using the calculations out of my copy of "WWII Ballistics: Armor and Gunnerery", the 0° resistance of the Sherman's 51mm glacis @56° comes out to 123mm, or 110mm with a 0.90 flaw multiplier (is this what's being used?). So the 75mm L/48 APCBC with 127mm penetration at 300m and 0° will most likely penetrate in this shot. However, if the tank were to have a 20° lateral angle to the firing tank, the compound angle would become 58°. Only two degrees can't make much of a difference, right? Not so. With the flaw multiplier, the 0° resistance for the 51mm glacis @58° becomes 120mm. That's a 10mm increase in resistance from just 2°. Give the tank a lateral angle of 30° and the compound angle becomes 61°. At this angle, the plate will have an effective resistance of 136mm, and now the 75mm L/48 has become unlikely to penetrate, all from just a 5° difference in shot angle. It's hard to judge from the screenshots how much this plays in this specific AAR, even the tank being just a few degrees nose up to PzKpfw IV and with some small lateral angle can give this much additional protection.

Btw, I am very saddened to hear about Lorrin Rexford Bird. I had been very excited to find him on this board after buying his book (and the principle reason I registered!), and had wondered why the E-mails we were exchanging dried up several years ago. He was definitely an expert in this, and all the calculations I made above were done straight out of his book.

[hoolaman]

First of all, thank you very much for all these detailed explanations. I really appreciate them !!

However, there is something that I am not understanding properly: when you speak about the hit results on the M4A3 Sherman, you state that:

“M4A3 Sherman upper hull: usually but not always penetrates; majority of killing energy absorbed by armor (53mm vs 46mm)”.

And later you also state referring again to the Sherman

“If the chance of a penetration from straight on is marginal, then a less optimal angle of impact likely means the round does not penetrate.”

But the chance of penetration should be quite high. 53mm vs 46mm should mean that most of the times the shell should penetrate. (53/46 = 1.15, penetration capability is 15% larger than the thickness of the plate). Then why do you speak about marginal chance of penetration? I think that in this case we have a high chance of penetration… and consequently if the Panzer IV hits the M4A3 Sherman three times with this high chance of penetration, it must be very unlucky not to penetrate it at least once. Not to achieve a penetration with 3 hits is possible, of course, but it is a very unlucky result for the Panzer IV.

Moreover, although the majority of killing kinetic energy would be absorbed by armor in case of penetration, the AP rounds used by the Panzer IV have an explosive filling to increase the destruction after penetration and therefore they should be able to produce important damage to the M4A3 Sherman.

Battlefront, could you please comment on these?

P.S. BTW, the ratios for the M4A3 Sherman hitting the Panzer IV at the upper hull and lower hull are quite similar: 96mm vs 80mm -> 96/80 = 1.20 (penetration capability 20% larger than the thickness of the plate) and 93mm vs 80mm -> 93/80 =1.16 (penetration capability 16% larger than the thickness of the plate) and in both cases you state that there will be a penetration.

I was wondering the same thing. Even with a small sample size the overperformance of the gun means that the odds are really stretched in favour of the Sherman. It would be nice if Bil could explain a bit more about where these rounds were impacting.

[Bil Hardenberger]

ShakyJake, I am not a numbers guy, but knowing, as I do, that formulas and data laid out in Rexford's book are exactly what the game is using, I have to trust the results.

Thanks for your explanation of Charles' information... all of that number crunching stuff is a bit over my head.

Bil