Radical Alternatives: How SHOULD Size and Speed/Range Affect Chance to Hit?

[vicky_molokh]

Looking more into it, and trying to visualise some of the propositions upthread, I think I'm leaning towards visualising the (mostly non-streamlined) modelling of a shot as a comparison of three circles (as spherical cows in vacuum):

• The projection of the actual target.
• The projection of the achievable area where bullets would likely fall.
• The projection of the target's positional uncertainty.

It seems like if the target's positional uncertainty is less than the bullet-cone projection uncertainty, then the former is of little relevance. Conversely, when positional uncertainty exceeds bullet-fall uncertainty, then it seems like a prudent thing to just expand the projection (cross-section) of the bullet cone and hope for the best hit. When the circles of uncertainty are comparable, things get messy and I'm not sure whether that's worth modelling.

But when one uncertainty significantly exceeds the other, it seems like it makes skill irrelevant, but maybe that's not quite the case. After all, the positional uncertainty is likely to have a cross-sectional area proportional to the square of the target's 'instant' speed times (reaction delay + bullet flight time). Because as a spherical cow in a vacuum, the target would hypothetically jerk in a random direction at non-enhanced speed, and the shooter would try to adjust for that. And the adjustment speed can perhaps be said to depend on skill level adjusted by gun unwieldiness (Bulk).

This seems to be heading towards the idea of the comparison consisting of picking the worst out of the two comparisons: gun skill + weapon accuracy vs. (quadratic-modifier) range, or gun skill + handling adjustment - flight time penalty vs. (quadratic-modifier) target's sudden-movement speed.

This seems to be heading towards invalidating the relevance of target dodge under some circumstances (when flight time is low but distance contributes more than sudden movements when it comes to the uncertainty circle).

[Andreas]

Originally Posted by vicky_molokh

This seems to be heading towards invalidating the relevance of target dodge under some circumstances (when flight time is low but distance contributes more than sudden movements when it comes to the uncertainty circle).

Invalidating the effect of random movement sure, but that is not all dodging. Dodging away from where you are predicting the attack to come (rather than a random direction) can still be a dominating factor. If done perfectly, it could even make the probability of hits zero.

[Anthony]

Originally Posted by vicky_molokh

This seems to be heading towards invalidating the relevance of target dodge under some circumstances (when flight time is low but distance contributes more than sudden movements when it comes to the uncertainty circle).

Flight time isn't really relevant except that it increases target positional uncertainty; if you can't see incoming projectiles, any pattern that's larger than your evasion radius and lacks identifiable gaps (such as hard cover you can duck behind) won't allow meaningful evasion (note that if you can see incoming projectiles, evasion beyond a certain distance will be 100%. This is rarely an issue for bullets vs infantry, but can be a problem for archery and unguided artillery against targets with radar).

[Ulzgoroth]

Originally Posted by Anthony

any pattern that's larger than your evasion radius and lacks identifiable gaps (such as hard cover you can duck behind) won't allow meaningful evasion

Uh, isn't a fire pattern that's larger than your evasion radius a rather unusual circumstance, and one where the incoming fire is generally going to be of low effectiveness?

Originally Posted by Anthony

(note that if you can see incoming projectiles, evasion beyond a certain distance will be 100%. This is rarely an issue for bullets vs infantry, but can be a problem for archery and unguided artillery against targets with radar).

Are there real situations where a target with radar can dodge artillery, or just hypothetical ones? I can't think of anything I'd expect to be able to be targeted by artillery that could detect unguided artillery shells and then maneuver around them except maybe small (and comparatively agile) ships. Aircraft in flight aren't targets for that kind of thing, and I didn't think most ground-based radars could pick up and run on a few seconds notice.

[Rupert]

Originally Posted by Fred Brackin

"SM 3 to 5" Only the Zero would have been SM 3 and you'd had to have rounded up a lot to get anything but the largest 4 engined bombers to SM 5.

The big strategic bombers had 40+ yard wingspans and were over 30 yards long. That's an easy SM+8. HT gives both the Mustang and the Fw190 as SM+6.

[Anthony]

Originally Posted by Ulzgoroth

Uh, isn't a fire pattern that's larger than your evasion radius a rather unusual circumstance, and one where the incoming fire is generally going to be of low effectiveness?

It's not at all unusual (it describes most automatic fire) and is quite low effectiveness per bullet.

Originally Posted by Ulzgoroth

Are there real situations where a target with radar can dodge artillery, or just hypothetical ones?

Naval gunfire. Flight time could exceed a minute in battleship duels.

[dcarson]

Originally Posted by Anthony

Naval gunfire. Flight time could exceed a minute in battleship duels.

One dodge method was to chase the splashes. If the last shell hit there they will correct so the next one won't. Works until they realize that you are doing it and don't correct the next salvo.

[Fred Brackin]

Originally Posted by Rupert

The big strategic bombers had 40+ yard wingspans and were over 30 yards long. That's an easy SM+8. HT gives both the Mustang and the Fw190 as SM+6.

3e sources thought of SM as a linear measure. I tend to think in Spaceships terms these days where SM is firmly tied to mass. Spaceships SM+3 is 3 tons, SM+4 is 10 tons and SM+5 is 30 tons. SM+8 would be 1000 tons.

[Tomsdad]

Originally Posted by dcarson

One dodge method was to chase the splashes. If the last shell hit there they will correct so the next one won't. Works until they realize that you are doing it and don't correct the next salvo.

Yep, or even turning into them, if you haven't already done this to make yourself a herder target.

Turning into Torpedo spreads as well would I think count for this (as in trying to adjust your position so you are not where the attack is)

[Rupert]

Originally Posted by Fred Brackin

3e sources thought of SM as a linear measure. I tend to think in Spaceships terms these days where SM is firmly tied to mass. Spaceships SM+3 is 3 tons, SM+4 is 10 tons and SM+5 is 30 tons. SM+8 would be 1000 tons.

Given we're talking about hitting the thing, size matters here, not mass, and aeroplanes are not very dense (especially WWII aircraft) and are thus large for their mass.