Monday, April 7, 2014

Introducing... The Survival Time Calculator

On a few previous articles, I've referenced a calculation I've done called Survival Time.  The survival time is a metric using characteristics of both the weapon firing and of the target in order to calculate the expected survival time of a single ship being fired upon by a single weapon.  I've built an online calculator that you can use in order to calculate Survival Time for your own ship designs.

What is Survival Time Really?

Survival time is the expected time that a single ship will survive when being fired upon by a single weapon, calculated in seconds.

Shipbuilding tools like the BP Outpost and Huggy's Ship Builder calculate Weapon DPS and/or Damage Taken from various weapon types.  At its simplest, survival time is Damage Taken divided by DPS.  However, my calculator also accounts for characteristics like Evade, Bonus Damage types, and Plate Armor.  

What Isn't Accounted For?

My calculator isn't perfect - I've listed the limitations I know about below.
  • Building Damage: I have used the ship damage values for all weapons - for weapons that have different building damage, you'll have to do some work yourself to calculate the expected survival time of buildings.
  • Specials: The weapon statistics are unmodified by any specials, such as Auto-Loader or Concussive Warhead.
  • Plate Armor: Kixeye has explained that there is a minimum weapon damage, even if plate armor would cause the calculated damage to be less than zero.  We don't know what that minimum actually is, I have used 0.001 as the minimum damage, but this is probably too low.
  • Countermeasures: Any active countermeasures on the target ship are not accounted for.
  • Splash Weapons: For Splash weapons (Mortars & Rockets), I use the formula Splash / (3/8 * Spread) to calculate an equivalent accuracy.
  • Salvo Time: I have used some generally accepted values for the salvo intervals.  They can be changed.  For Halo & Brimstones I use a 6 salvo with a zero interval to simulate the 6 simultaneous pieces.
  • Accuracy / Splash combo:  For weapons that have both an accuracy and splash statistic, I have ignored the splash and used accuracy only.  (Siege Cannon W, S, Z)
  • D-92U Launcher: The launcher Shockwave is not accounted for - only the direct hit damage is included in the calculation.
  • "Half Damage": It has been stated on the forums that weapons actually do half of their rated damage points against targets.  I'm not sure if that is true or false, and so I have used all weapon and armor statistics as listed in their blueprints.
  • Selection of Weapon Types: I have not entered information for every weapon in the game, just a selection of weapons I think may be important.

How Do I Use the Tool?


To use the tool, you should have one to three ship designs that you would like to compare, and go to the Calculator page at http://bpprofcalc.blogspot.com

For each design, you need to know the total armor points, evade %, % resistances to each of the 5 damage types, and plate resistances (subtraction) to each of the 5 damage types.  See figures below for the location of the needed data.


Circled data is required - Huggy's Ship Builder


Circled data is required - BP Outpost.com shipyard.  You will need to figure out plate information for yourself.

Enter the data for each ship design in a column.


This example shows two different hull configurations being compared.

Enter the data related to applicable hull and alliance bonuses in the row by each weapon type.  This is broken up by weapon type because some bonuses apply only to particular weapon types.  For example, the alliance Defender bonus applies only to base weapons, or the Stingray Accuracy bonus applies only to Ballistic weapons.  The default reload bonus in the calculator is 35% - 25% from rank and 10% from alliance gunner bonus.  The default accuracy bonus is 20% from alliance gunner bonus.  For mortar and rocket weapons, a splash bonus is used instead of accuracy.  This could be from a hull bonus or a special such as High Explosive Shells.  UAVs have a damage bonus, which could be from Powercells.


Enter the weapon bonuses in the circled areas.


Each row lists the expected survival time for each design against a particular weapon.  If you are evaluating ship designs, the one with the largest number is the best, since that ship would be expected to survive the longest.  The tool automatically shades the survival times from Green to Red for best to worst in each row.

Why Would I Use the Tool?

This tool helps to compare different armor / special configurations, in order to figure out what would last longer against different types of weapon fire.  

Another way to use the tool is to evaluate different weapons against example ships.  The picture above shows how much less effective a Halo is than a Brimstone, since the Halo has a 431.6 second survival time vs a 349.9 second survival time against the ship configuration being compared.

Any weapon not included in the tool can be entered by typing over the statistics of an existing weapon.  Fix any screwups by reloading the page.


Conclusion

I hope this tool is useful - the page is kept up like a blog, and I put release notes below the table.  Use it in conjunction with a ship builder tool, not instead of one.  I'll try to keep it up do date with new weapons. Leave any thoughts and feature requests as comments on that page and I'll try to address them in updates.

The site for the calculator - http://bpprofcalc.blogspot.com