User:John Ember
Who is John Ember?
And why is he so fascinated with zinnias?
John Ember  


MBR Weapon Rating System
Weapon  MBR  MBR against flak 
Survivors  
Pistol  1.71  1.37 
Shotgun  1.17  0.93 
Flare Gun  0.11  0.09 
Fire Axe  1.2  1.2 
Kitchen Knife  0.8  0.8 
Length of Pipe  0.5  0.5 
Baseball Bat  0.5  0.5 
Crowbar  0.4  0.4 
Fist  0.25  0.25 
Zombies  
Claws  1.71  1.71 
Bite  1.52  1.52 
Remember, this is an overall effectiveness rating! Don't take this to mean you should only use the pistol against enemies with flak jackets, or never use the shotguns you collect. In combat, you should usually employ the weapon which will allow you to do the most damage for the least AP at the time. The MBR measures the overall relative effectiveness of weapons, not their suitability to particular combat situations. 
The MBR, or Median Battle Rating, is a measure of a weapon's average effectiveness over time. Because firearm weapons must be restocked, assessing them only on the basis of their incombat effect artificially inflates their perceived usefulness. In order to make sense of the relative effectiveness of all Urban Dead weapons, I offer the MBR weapon rating system.
In all cases, we assume skills are maxed. Searching for consumable ammo is calculated in; searching for nondestructible items (the fire axe or the firearm itself) is not. Searched buildings are assumed to be powered. (Note: the April 29th game update boosted search rates for powered buildings. Data on the new search odds is still coming in; expect the firearm ratings to fluctuate slightly for a while yet.)
The formula is (damage * hit rate) divided by (search AP + load AP + attack AP). Note that "search AP" and "load AP" refer to how many AP it takes to find and load a single shot; in cases like the pistol where several shots can be found or loaded at once we have to adjust for this by representing those values as fractional AP.
Survivor attacks
Pistol: about a 23% chance of finding a clip's worth of (six) bullets (including bullets already in pistols when found) in a mall with Bargain Hunting. That works out to be 4.34 AP per clip, or 0.73 AP per round. Add 1/6 (0.17) AP for load and 1 AP for fire; total is 1.9 AP per fired round. Each round has a 65% chance of doing 5 damage  3.25 average. Thus, overall average damage is 3.25 hp per 1.9 AP, or 1.71 MBR. Against a flak jacket, it's 1.37 MBR.
Shotgun: about a 28% chance of finding a single shell (including those already in shotguns when found) in a mall with Bargain Hunting. Works out to be 3.57 AP per shell. Add 1 AP for load and 1 AP for fire; total is 5.57 AP per fired round. Each round has a 65% chance of doing 10 damage  6.5 average. Thus, overall average damage is 6.5 hp per 5.57 AP, or 1.17 MBR. Against a flak jacket, it's 0.93 MBR.
Flare Gun: about a 5% chance to find a flare in a fire station. That works out to be 20 AP per flare. Add 1 AP for fire; total is 21 AP per fired round. Each round has a 15% chance to do 15 damage  2.25 average. Thus, overall average damage is 2.25 hp per 21 AP, or 0.11 MBR. Against a flak jacket, it's 0.09 MBR.
Fire Axe: 40% chance of doing 3 damage  1.2 average per AP, thus 1.2 MBR.
Kitchen Knife: 40% chance of doing 2 damage  0.8 average per AP, thus 0.8 MBR.
Length of Pipe, Baseball Bat: 25% chance of doing 2 damage  0.5 average per AP, thus 0.5 MBR.
Crowbar: 20% chance of doing 2 damage  0.4 average per AP, thus 0.4 MBR.
Fist:  25% chance of doing 1 damage  0.25 average per AP, thus 0.25 MBR. Still better overall than the flare gun!
Zombie attacks are less straightforward for the MBR formula because the hit rate actually changes as Tangling Grasp goes in and out of effect. To accommodate this, I take 95% of the max Tangling Grasp hit rate. This brings the results pretty well in line with Siddhant's more developed math on the subject, which you are welcome to check out.
Zombie Claws:  About a 57% chance of doing 3 damage overall. 1.71 average per AP, 1.71 MBR.
Zombie Bite:  About a 38% chance of doing 4 damage overall. 1.52 average per AP, 1.52 MBR.