Benefits and risks of hull down battle positions

[Pelican Pal]

I've run some tests on hull down performance and they've shown some interesting info regarding hull down in Combat Mission. The tests were done using two Panthers engaging each other one hull down and the other hull up.  The range was 700 meters and the hull up tank drove into view of the hull down tank. Both crews turned in.

Results of 62 tests

Victories:
Hull down: 37
hull up: 24
Draw: 1

The hull down tank won 60% of the engagements.

- Being hull down represents a good chance to win a given engagement.

Spotting

hull down spotted the hull up tank 59 times
hull up tank spotted the hull down tank 31 times

The hull down tank spotted the hull up tank 95% of the time while the hull up tank only spotted the hull down tank 50% of the time.

- Being hull down gives significant protection from being spotted/advantage in spotting.

Victories in instances where the hull up tank spotted the hull down tank (31)

Hull down: 7
hull up: 24

The hull up tank won 77% of the engagements where it was able to spot the hull down tank.

- Having a fire fight from a hull down position can be very risky for certain vehicles.

Avg shots before the tank hits its opponent
Hull Up: 1.4
Hull Down: .57

Avg shots before the tank kills its opponent
Hull Up: 1.4
Hull Down: 3.08


Summary:

The primary benefit of hull down in CM is a buff to the vehicles concealment.  There is a secondary benefit in that the hull down vehicle is harder to hit. However, this is counterbalanced by a much higher number of shots needed to ensure a kill. Although this will vary based off of the armor of the two tanks engaging.

My thoughts:

- When engaging hull down enemies try to gain spotting bonuses to reduce the concealment bonus. Its a large portion of the hull down advantage.

- If your tank's turret armor is relatively weak be wary of engaging in a shoot out from hull down. Ideally you are engaging and moving before being spotted. If you are expecting to have to engage in a shoot out it may be beneficial to exit hull down after the concealment bonus is lost or there may be nearby locations (keyhole for example) that could be more beneficial than the hull down position.

Edited February 8, 2022 by Pelican Pal
clarity

[Bulletpoint]

I think the Panther is not the best tank to test this with, as the strong front hull armour will somewhat skew the results.

Better to test two PzIV against each other to isolate the hull-down factor.

In actual historical matchups, things will of course change depending on what exactly is shooting at what.

[Rinaldi]

25 minutes ago, Pelican Pal said:

The hull down tank won 60% of the engagements.

- Being hull down represents a good chance to win a given engagement.

I was going to warn you they're coming but I see @Bulletpoint has already arrived. I trust you found cover before this happened. 

[Pelican Pal]

16 minutes ago, Bulletpoint said:

I think the Panther is not the best tank to test this with, as the strong front hull armour will somewhat skew the results.

Yea. It why I bolded the below portion:

 

35 minutes ago, Pelican Pal said:

Although this will vary based off of the armor of the two tanks engaging.

The decisions being made are going to vary heavily based on your vehicles and your opponents vehicles. For example, if you have a Panzer IV against an M36 then hull down is more beneficial since the M36 has over kill against so you want the concealment and chance to hit protection.

 

9 minutes ago, Rinaldi said:

I was going to warn you they're coming

I don't follow but obviously hull down is a beneficial position to start any fight in since you gain such a large concealment bonus. The HD tank is spotting 95% of the time which is H U G E . The complexity for the hull down tank occurs once it has been spotted (and then only if its turret armor is particularly weak). In those situations you want to essentially ambush from hull down and then move to another battle position. Where the hull down tank starts to run into problems (sometimes) is if you get into a true fire fight with both tanks trading fire.

Part of the problem is that you aren't always going to have another good battle position to move to and may be forced to engage in a firefight.

 

Edited February 8, 2022 by Pelican Pal
HD

[Pelican Pal]

To focus this a bit the common sense position would be that hull down tanks are much harder to hit. AKA "its better for incoming rounds to hit dirt than your face". But whats panning out in the above test is that incoming rounds aren't hitting dirt that much more often.  The real benefit in CM is that there just won't be incoming rounds at all.  The benefit isn't that you are significantly harder to hit but that you are significantly harder to spot in the first place.

So if your tank has a weak chin then engaging in an honest to god shoot out (where the enemy has spotted you and is firing back) isn't going to be great for it. In fact your are much more likely to take damage. So you either want to avoid the shoot out (new battle position and so on before they spot you) or take the shoot out from a hull up position.

[Rinaldi]

5 minutes ago, Pelican Pal said:

So if your tank has a weak chin then engaging in an honest to god shoot out (where the enemy has spotted you and is firing back) isn't going to be great for it. In fact your are much more likely to take damage. So you either want to avoid the shoot out (new battle position and so on before they spot you) or take the shoot out from a hull up position.

Exactly. 

[Pelican Pal]

Just now, Rinaldi said:

Exactly. 

Yes, that is my point? I gathered you have some issue with my conclusion but I can't figure out what it is.

Possibly just a misunderstanding over text

[Rinaldi]

Yes, I presumed the worst at one of your phrases - you will have to forgive me on that. There has been, in the past, some extremely wild conclusions based on the simple data. Very heartened to see you reached the natural, easiest conclusion. It's a breath of fresh air for this discussion. 

[Dynaman216]

Cancel that...

Edited February 8, 2022 by Dynaman216

[Dynaman216]

Does that average shots before a hit is scored mean an HD tank is hit quicker than one that is not?  That is very strange.

[Pelican Pal]

 

30 minutes ago, Dynaman216 said:

is off if it is worse for a tank with bad turret armor to be hull down then to not be hull down. 

To be clear its better for any vehicle to start hull down as there is a very significant concealment bonus and that concealment bonus can be turned into a kill (more efficiently with bigger guns). What you want to watch out for is (with certain vehicles) engaging in an honest to god fire fight where you are trading shots with the enemy. Since so much the hull down bonus is in concealment you are losing a lot of advantage once that happens.

For sake of argument you have a Panther with 2 hull down positions and then finally a position that is hull up. It is being attacked by a large armor force. You would want to start the fight from the first position and then maneuver to the second position before being spotted. However, once you have been spotted at the second position you would not want to continue fighting from it but move to the hull up position.
 

Edited February 8, 2022 by Pelican Pal
spotting to concealment

[Pelican Pal]

2 minutes ago, Dynaman216 said:

Does that average shots before a hit is scored mean an HD tank is hit quicker than one that is not?  That is very strange.

I updated the text but its the number of shots needed by the tank to hit its opponent. So vice versa of what you typed.

[scrappie]

Nice set of tests.

One question though - how can the number of shots before the hull down tank hits its opponent be less than 1?

[Bulletpoint]

10 hours ago, Rinaldi said:

I was going to warn you they're coming but I see @Bulletpoint has already arrived. I trust you found cover before this happened. 

Nice to see you too.

[Chibot Mk IX]

I have question on how this was handled ?

Quote

“The range was 700 meters and the hull up tank drove into view of the hull down tank.”

 

I have concern this brings some variations into your testing and project their own unique influence on the result.

Drifter Man’s “Some tank duel tests (CMBN)” found out that the stationary side has a huge spotting advantage compared to the moving side (Table #3)  

[Pelican Pal]

1 hour ago, Chibot Mk IX said:

I have concern this brings some variations into your testing and project their own unique influence on the result.

Originally I did testing where both tanks spawned in LOS of each other but I noticed that hull down was doing quite a bit worse than I would have thought. Naturally though it would be unusual for two tanks to spawn in LOS of each other so instead I went with the more common (to my mind) setup of having a tank drive into view of a hull down vehicle.

As Rinaldi mentioned there are sometimes threads to the effect that hull down shouldn't be used. Its common to dismiss these claims out of hand but I wanted to delve into what players might be doing to cause hull down to be less effective. It seems that engaging in a fire fight from hull down does not have a large protective benefit... Again because most of the protective benefit is in the concealment buff. So if a player is repeatedly taking fights from hull down they might be coming into it believing that its not worthwhile when in reality their particular usage of hull down is throwing away much of the benefit.

Now to fully expand the tests I should also have the hull down tank drive into its fighting position.


 

 

12 hours ago, scrappie said:

One question though - how can the number of shots before the hull down tank hits its opponent be less than 1?

If the first shot hits the opposing tank then it would take 0 shots to find the range.

[Thewood1]

I would think moving vs. non-moving would be a pretty big influence on spotting and even hitting first shot.  Did you test this against no hull down and one tank moving into sight?  Otherwise, I think its hard to separate whether hull down or moving has more influence.

[Pelican Pal]

I did run a test of 16 tanks under the same circumstances except both tanks were hull up and the results were:

Victories
Mover: 7
Static: 7
Draws: 2

Avg shots before the tank hits its opponent
Mover: .71
Static: .63

Avg shots before the tank kills its opponent
Mover: 4.2
Static: 3.6

Spotting rate
Mover: 80%
Static: 100%

Unlike the hull down version of this test the times when the moving tank did not spot the static tank was due to the mover being killed within seconds of test start. During the HD test there were a number of instances where the HD tank was not spotted for multiple minutes. In one instance the HD tank was able to fire its entire ammo load without being spotted.

I would have preferred doing a larger test group as the hull down version had nearly 4x the number of runs.

Edited February 9, 2022 by Pelican Pal

[Thewood1]

I'm a little stunned the movers got equal kills to the non-movers.  That seems to go against everything I remember BFC telling us about moving and buttoned tanks have significant disadvantages in spotting.

 

Some of that shows up in some of the stats, yet the equal outcomes belies that.

[Pelican Pal]

39 minutes ago, Thewood1 said:

I'm a little stunned the movers got equal kills to the non-movers.  That seems to go against everything I remember BFC telling us about moving and buttoned tanks have significant disadvantages in spotting.

So I highly recommend you check out Drifter Man's testing of moving/stationary. That will inform you better of the stats for that particular type of fight.

However I think there is some misunderstanding here. In the editor I built a LOS block and then had the "attacker/hull up" vehicles move through that LOS block and stop immediately after clearing it. So they were moving for maybe 20-30 meters at the most. This gives the stationary vehicle some advantage but for the balance of any test both vehicles were stationary.

[Thewood1]

Would it be possible to post the scenario(s).  I'd like to play around with them a little.

[chuckdyke]

11 hours ago, Pelican Pal said:

I wanted to delve into what players might be doing to cause hull down to be less effective.

It is camping once your 'Hull Down' position is known, and you remain there you are on borrowed time. Case in point is Seelow in Fire and Rubble. 

[MikeyD]

Perhaps its my imagination, but it seems if you use the 'hull down' movement command instead of doing it on your own the opposing tank's first round will tend to go high and the second impact the ground in front of you before finding the range. The game seems to have built-in the initial rounds struggling to find their mark. If you move to the same position in the normal manner the chance on seen a ground impact ahead of you is negligible.

[Darth Panzer]

9 hours ago, MikeyD said:

Perhaps its my imagination, but it seems if you use the 'hull down' movement command instead of doing it on your own the opposing tank's first round will tend to go high and the second impact the ground in front of you before finding the range. The game seems to have built-in the initial rounds struggling to find their mark. If you move to the same position in the normal manner the chance on seen a ground impact ahead of you is negligible.

This sounds correct as mentioned by MickyD.

[Lethaface]

23 hours ago, Pelican Pal said:

Originally I did testing where both tanks spawned in LOS of each other but I noticed that hull down was doing quite a bit worse than I would have thought. Naturally though it would be unusual for two tanks to spawn in LOS of each other so instead I went with the more common (to my mind) setup of having a tank drive into view of a hull down vehicle.

As Rinaldi mentioned there are sometimes threads to the effect that hull down shouldn't be used. Its common to dismiss these claims out of hand but I wanted to delve into what players might be doing to cause hull down to be less effective. It seems that engaging in a fire fight from hull down does not have a large protective benefit... Again because most of the protective benefit is in the concealment buff. So if a player is repeatedly taking fights from hull down they might be coming into it believing that its not worthwhile when in reality their particular usage of hull down is throwing away much of the benefit.

Still on this?

It's always good to remember exactly what you're testing. In the setup of 2 identical tanks (1 hull down, 1 not hull down) which have spotted each other and are duking it out, you are mainly testing the offset between the advantage of presenting a smaller target vs presenting strongest armor at 'center mass aimpoint'. 

Without having done any tests, I predict there will be a large variance in results from:

* Gun accuracy: with a less accurate gun, more rounds will impact off center mass aimpoint.
* Range: (as a factor of gun accuracy; at longer ranges relatively less rounds will exactly impact the center mass aimpoint. While point blank all rounds will exactly impact center mass).
* The relative strength of turret armor vs 'center mass aimpoint' armor (which in case of Panther is stronger than turret armor)

There is also a brute fact to consider:

* For any tank with stronger turret armor compared to hull armor there is principally nothing to gain ever by any rounds impacting the hull over the turret.

So, whatever it is the test results will tell you, you'll have to consider that the results will vary for different tanks and different ranges. The question is what value the results will give anyone regarding 'actionable information'. My impression is: zero. 

Logic predicts that for tanks with stronger hull armor than turret armor, you'd rather take a hit on the hull than on the turret. 

Concluding: when you have a Panther and you are in close range to other tanks that have spotted your tank and for some reason you feel like Dirty Harry and have a good shoot out with enemy (instead of reversing to cover and reposition), don't bother with hull down but present that cheeky hull armor in the enemy face!

In all other cases: bother with hull down and don't engage in honest to God duels if you don't need to. 

Edited February 10, 2022 by Lethaface