Battleship (Mikasa) Dispersion

[Detonator53]

I am a little confused and frustrated with the concept of dispersion.  It's my understanding that the numbers reported by WG are the maximum dispersion at maximum gun range.  I'm using the Mikasa for this example because the numbers are smaller and easier for us all to imagine in our heads.  The Dispersion is listed at 142 meters at 9.5 km.  If we reduce that by 2/3, we end up with a dispersion of almost 50 meters at just over 3 km.  Please correct me if I'm doing this wrong.  I just had a game and I watched my shells, targeted at another Mikasa's main gun deck, fall half way between me and my target.  Now a little geometry here.  If you imagine the line of sight of my aim as the base line to the target, with a perpendicular line at the target being 50 meters that should allow us to make a circle with a 50 meter radius representing my dispersion cone at 3km.  So imagine a worst case scenario, where my shells are fired above my barrel and arch down into the water to meet that point that's 50 meters below my aim point (just above the gun deck of my target.  In order for those shells to hit that point 50 meters below my aim point (point of impact) and enter the water at half the distance to my target (1500m) they would have to travel almost straight from my gun barrels to the point of impact. It seems to me that since my guns are slightly elevated that this is impossible.  Two possible explanations come to mind; 1 - the animation is simply that and not a real representation of the shell firing action and simply represents a 'miss', and 2 - the maximum dispersion is inaccurate.  I wont even mention the third possibility, that the shells fell out of my gun barrels due to improper powder charging and just went "thud" into the water.  Can someone please explain this phenomenon ?

 

I would be particularly interested in an official explanation if it's simply an animation, so that we can put this topic to bed quickly.

 

I would also invite anyone with unusual observations of shell tracks to share their experiences.

 

Thank you for listening.

 

[Stratego89]

Now... I could have misunderstood you here, but from the sounds of it you were locked onto one target and aimed at another target. When you lock onto a target, the way the fire control works changes entirely. Think of it as "not locked on" = fire exactly where in the water you are aiming at; and "when locked on", where you aim in relation to the target shifts the fire from the target. When you're locked on, it's set to fire at that target, you're just adjusting at that point where in relation to the target it will go and even if you aim really really low it's not actually going to go there, as you're just shifting the relation to the target rather than the actual aim point. I could be wrong about all this, but I believe that's how it works.

[Detonator53]

Now... I could have misunderstood you here, but from the sounds of it you were locked onto one target and aimed at another target. When you lock onto a target, the way the fire control works changes entirely. Think of it as "not locked on" = fire exactly where in the water you are aiming at; and "when locked on", where you aim in relation to the target shifts the fire from the target. When you're locked on, it's set to fire at that target, you're just adjusting at that point where in relation to the target it will go and even if you aim really really low it's not actually going to go there, as you're just shifting the relation to the target rather than the actual aim point. I could be wrong about all this, but I believe that's how it works.

 

Yes, you are mistaken, there is only one target.  Thank you for reading/replying.

[Stratego89]

 

Yes, you are mistaken, there is only one target.  Thank you for reading/replying.

 

Ok, just took the phrasing of something the wrong way then.

 

The only other explanation I can give for you is "distance in WoWS is very very strange". If you compare ships' supposed length to actual in game distances, the distances are ludicrously small-scaled. EG if you put 1 yamato's distance in between two yamatos, the back yamato is actually MUCH LESS than one yamato's length in "distance" to the other yamato, according to the game. Put more clearly let's say the yamato was 10 meters in reality. The Yamatos are "one yamato" or 10 meters apart. However the scope would report it is a mere 2 meters apart. Those are obviously made up values but I'm just trying to get the point across.

[Aduial]

Sometimes i stare in amazement, as i fire at a target and all of my shells fall short, or go over the target by a huge margin. I don't know how dispersion can be that terrible. 

[godzilla5549]

You see, your first problem was firing the main guns on Mikasa.

[Stratego89]

Sometimes i stare in amazement, as i fire at a target and all of my shells fall short, or go over the target by a huge margin. I don't know how dispersion can be that terrible. 

 

If all of your shells are falling above your target or all of your shells are falling below your target, it's not dispersion, sorry to say.

[Stratego89]

You see, your first problem was firing the main guns on Mikasa.

 

Everyone always makes jokes like this, but those main guns are a force to be reckoned with. They're not nearly as horrid as people act like they are.

[DerKrampus]

You see, your first problem was firing the main guns on Mikasa.

 

You mean my 4 large-caliber secondary guns?

Because I'm typically too busy trying to get within range of my 16 or so full-auto primary guns to bother with them.  xD

[Aduial]

 

If all of your shells are falling above your target or all of your shells are falling below your target, it's not dispersion, sorry to say.

 

No, it happens with the Mikasa. I aim at the waterline, from 5km, and the guns just go all over the place. 

[vak_]

If we reduce that by 2/3, we end up with a dispersion of almost 50 meters at just over 3 km

 

Why do you assume the dispersion change with distance is linear? It's definitely not. This fuso dispersion analysis is pretty old, but I doubt the dispersion model changed much since then. Note how the fit is at least a second degree polynomial; maybe more (I only had three points unfortunately). Below 4km, IIRC, there is also rapid dispersion improvement which was a buff to BBs sometime last year.

 

 

 

You also misunderstand what port dispersion value means. Shells can and will land outside it. The value that's shown to you in port is the horizontal axis of the dispersion ellipse at maximum range, specifically it's one probable error (i.e. we expect 50% of shells to land inside that distance that is centered around the point of aim).

[Stratego89]

 

No, it happens with the Mikasa. I aim at the waterline, from 5km, and the guns just go all over the place. 

 

I'll repeat it again... if your rounds are ALL going above OR below the target... it's not dispersion... it's your aim. If your shots go above AND below a target in one salvo... then it's dispersion. You stated the former, not the latter.

[Fetchez_la_Vache]

Max dispersion starts at the end of the muzzle.  Eithert the rounds just fall out of the barrels or they return to earth covered in ice   If I ever get the Training Room, 12 v 12 Mikasas will happen 

 

[jkirschy]

Probably worth pointing out that (at least with Mikasa), there is dispersion and then there are fire-control issues due to it being a pre-dreadnaught. People tend to overlook this for some reason, but the Mikasa's fire-control systems were designed at a time when 5000 meters was considered extremely long range and full caliber, long-range, gunnery practice was routinely carried out at 1500 meters. So I suspect some of the derpy performance you're seeing with Mikasa when you're at the outer edge of the pre-dreadnaught effective range envelope is due to fire control issues that Wargaming modeled into the game. And I suspect that Vakhnenko is right that some of it is due to dispersion not being a linear progression.

 

As an aside, for those who doubt the range figures I tossed out for pre-dreadnaughts... If you read the official reports filed, at the Battle of Manila Bay the engagement range varied from 3,000 to 5,500 yards. When William Sims and Bradley Fiske counted the holes in the Spanish ships after the battle and compared it to what was fired, the hit ratio was about 1-2%. Surprisingly their superiors considered that good accuracy, though both Sims and Fiske believed that it wasn't good enough and made pests of themselves trying to effect change. The performance of the USN at Santiago de Cuba was materially the same, aside from a lucky shot or two by Oregon while running down Cristobal Colon. And if you read the account of Tsushima that Anthony Preston gives in Battleships, you'll find that while Togo's fleet opened fire at around 7,000 meters, they didn't hit much until the range fell considerably. So yeah... pre-dreadnaughts... gotta get closer than you think for the main guns to do much.

[MJPIA]

Max dispersion starts at the end of the muzzle.  Eithert the rounds just fall out of the barrels or they return to earth covered in ice   If I ever get the Training Room, 12 v 12 Mikasas will happen 

 

You can't.

You can take a Mikasa into the training room but you cannot select premium ships from the list to put in as bots so no world of Mikasa's.

 

[Fetchez_la_Vache]

 

You can't.

You can take a Mikasa into the training room but you cannot select premium ships from the list to put in as bots so no world of Mikasa's.

 

 

My soul...... crushed    I'm gonna need a few minutes....

[Aduial]

 

I'll repeat it again... if your rounds are ALL going above OR below the target... it's not dispersion... it's your aim. If your shots go above AND below a target in one salvo... then it's dispersion. You stated the former, not the latter.

 

Sorry, i think i worded my sentence badly. I meant, some of my shells go over and some go below, and all shells miss. 

[Detonator53]

Why do you assume the dispersion change with distance is linear? It's definitely not. This fuso dispersion analysis is pretty old, but I doubt the dispersion model changed much since then. Note how the fit is at least a second degree polynomial; maybe more (I only had three points unfortunately). Below 4km, IIRC, there is also rapid dispersion improvement which was a buff to BBs sometime last year.

 

 

I do appreciate the charts, and while I don't want to debate higher math with you, I'm only talking about 3 kilometers, and I can't imagine the deviation from a straight line being all that much.  I would love to see such graphs for the Mikasa.  I know about the close range dispersion buff to BBs, but I haven't actually noticed it.  Any further thoughts on the animation of the shell path being simply an animation and not representative of the shells actual flight ?

 

[Detonator53]

As an aside, for those who doubt the range figures I tossed out for pre-dreadnaughts... If you read the official reports filed, at the Battle of Manila Bay the engagement range varied from 3,000 to 5,500 yards. When William Sims and Bradley Fiske counted the holes in the Spanish ships after the battle and compared it to what was fired, the hit ratio was about 1-2%. Surprisingly their superiors considered that good accuracy, though both Sims and Fiske believed that it wasn't good enough and made pests of themselves trying to effect change. The performance of the USN at Santiago de Cuba was materially the same, aside from a lucky shot or two by Oregon while running down Cristobal Colon. And if you read the account of Tsushima that Anthony Preston gives in Battleships, you'll find that while Togo's fleet opened fire at around 7,000 meters, they didn't hit much until the range fell considerably. So yeah... pre-dreadnaughts... gotta get closer than you think for the main guns to do much

 

Thank you for your reply.  I am quite familiar with the battle of Manila Bay, and I've actually been on the USS Olympia, which is currently docked in Philadelphia, PA.  I agree that the actual performance in real life is very poor when expressed as a percentage of shell hits, but we are talking about actual experience in-game, and at 3km.  What are your thoughts regarding the idea that shell animations are simply that and not representative of the actual flight path of that particular shell ?

[DeMatt]

Considering that rapid-fire ships like Cleveland and USN DDs can "walk" their shells up and down a target, hitting areas of choice, I'd say that the displayed flight is, barring network problems, representative of the calculated flight.

 

Try drawing it out, using Paint or something so you have pixel-perfect rulers and lines.  Mikasa's guns are about 10 metres above the waterline, shooting at a water-surface target 3000 metres horizontally away.  Assume the shots diverge in a perfect cone (from each gun barrel, so better to consider one single gun), the apex of which is at the gun and the base of which is 50 metres in diameter.  Where does the plane of the water surface intersect the cone?  If you move the target up 10 metres (so the cone's straight horizontal), where does the water intersect the cone?

 

It's my understanding that ships are actually scaled up quite a bit relative to the distances displayed, to make hits easier.  Navies in both world wars would have loved to have our accuracy rates - one-third hits at combat ranges?  Yes please!