Automatic Combat Stats Calculator

[bluejay]

Hi everyone,

The large conversation about the new combat system has prompted me to investigate the statistics involved.

I've posted up a preliminary page at http://www.genomia.co.uk/mrqstats.html

Basically you enter the attacker's % chance to hit, then the defender's % chance to dodge or parry and it brings up results.

Initially I summarise some important stats and then I detail each and every situation.

I hope people find this useful. I felt it was interesting to test across the 100% margin (i.e. difference between 100% to hit and 101% to hit) due to skills over 100% being halved in opposed tests.

The functionality of the page has been written in JavaScript and I've left it in the page with comments to allow others to check my work and conclusions.

Enjoy people!

 

[Ravage]

tis really cool....

heh, for a laugh, why not add a "roll dice button" and highlight so that people can get the java to randomly try your probabilities

...or advance yourself to doing a nice online charcater/monster generator

 

[Rurik]

Don't you realize that cold hard numbers takes all the fun out of arguing about these things on the boards!

No, really, thanks for the effort. It's good to see someone was actually doing something rather than just arguing.

Wanna Ref the volleyball game?

 

[Archer]

Thank you for this one, hard cold numbers really show what we have been arguing.

 

[bluejay]

Ahhhh... I clearly fumbled my Computer Programming skill roll and I'd been miscalculating the result for dodging characters getting hit.

I've rectified this and published a 1.0.1 version now which should be correct.

regards

 

[Archer]

Ahhhh... I clearly fumbled my Computer Programming skill roll and I'd been miscalculating the result for dodging characters getting hit.

I've rectified this and published a 1.0.1 version now which should be correct.

regards

Thank you

 

[bluejay]

Ok, so I've now started taking some readings on this and it does seem that people are correct about this.

If you wish to help expand the MRQPC (Probability Calculator) then please send me a PM. The code is pretty self-explanitory. It's also fairly easy to see how I've summarised the results at the top.

Anyway, here are some strange stats: -

Attacker: 70%, Defender (dodge) 100%

Chance that attacker hits for normal damage: 6.678%
Chance that attacker hits for critical damage: 0.987%

Attacker: 70%, Defender (dodge) 101%

Chance that attacker hits for normal damage: 30.81%
Chance that attacker hits for critical damage: 4.45%

Seems very strange to me and it looks like the system breaks down around these numbers.

 

[bluejay]

Just uploaded a new version of this which shows the calculations being used to ensure clarity.

 

[Archer]

Seems very strange to me and it looks like the system breaks down around these numbers.

It sure does. And as such it is not more of a fix than any other solution used in BRP clones in the past.

In fact, not using the halving rule would be a better fix, as long 96-00 is always a failure.
Though, then you still have the problem of two 100% fighters doing endless attack-parry-attack-parry-attack-parry with out it ever being resolved. And I suspect that this was what the halving rule was meant to fix.

 

[bluejay]

I've also noticed that this continues to get worse. So, when fighting an attacker with 100% attack, 200% is not bad for dodge but 205% is terrible! This isn't just a singularity around the 100% mark.

Also, it doesn't rely on a high attacker skill either. The parry and dodge opposed roll tables favour the attacker so strongly that any halving of the defender's skill always move significantly in favour of the attacker!

 

[Urox]

The parry and dodge opposed roll tables favour the attacker so strongly that any halving of the defender's skill always move significantly in favour of the attacker!

If the calculations are correct, going from 100 to 101 almost halves your Riposte chance as well...

 

[bluejay]

That seems quite intuitive as your chance to riposte is almost linearly dependent upon your chance to roll a critical parry (i.e. on the opposed table you can riposte if the attacker rolls anything other than a critical, provided you roll a critical parry).

As your critical parry chance halves when you go over 100% this in turn reduces your chance to riposte.

 

[Archer]

Hmm, just thinking; What would happen if the rule had been worked out so, that the % to crit was unchanged.

For example; Halving 110% to 60% would still retain the 11% crit chance.

It certainly would not be enough to make up for the loss of ability, but I wonder if at least would not give those with a very high skill score a much stronger advantage.

 

[Adept]

This is so flawed, and a classic example of the fact that the makers of RPG systems should have studied a bit more math at school.

Terrible

 

[atgxtg]

This is so flawed, and a classic example of the fact that the makers of RPG systems should have studied a bit more math at school.

Terrible

Hold on a second. Since the people who originally posted these examples seem to be in error the designers might be innocent. It is is treated as a single contest rather than two sequential contests the mathematics change, significantly.

The "two rolls" system had all the problems and complexities of a three stage rocket (same math, and why so many mutistage rockets fail).

I think I'll do a little crunching of a single roll halved skill/opossed resolution. I don't like it, but I think the math holds up much better.

 

[janoll]

Attacker: 70%, Defender (dodge) 100%

Chance that attacker hits for normal damage: 6.678%
Chance that attacker hits for critical damage: 0.987%

Attacker: 70%, Defender (dodge) 101%

Chance that attacker hits for normal damage: 30.81%
Chance that attacker hits for critical damage: 4.45%

Seems very strange to me and it looks like the system breaks down around these numbers.

Faced with what 'seems' to be statistical proof, as a consumer of Mongoose products I would like a response from Mongoose concerning the potential statistical anommolies in the combat system. As much as my group has been looking forward to MRQ, we won't buy into a system that is broken from the beginning. If there is a problem as described above, I think it goes beyond the stock statement of 'you can't please all the people all of the time' that I've seen as a reaction to other potential MRQ consumer's issues.

I'm not flame baiting I just want to hear from Mongoose if the above mentioned issue, in their opinion, requires errata; and if not why it is not broken. And since we have a statistical analysis showing a potential anomoly, Id like to see some numbers to back up their explination.

I'd like to see this before I give them my $25.

Thanks

Joe
Lost in WV

 

[bluejay]

On another thread I've now read a post which states that although there are two rolls (attack roll, followed by opposed roll) the opposed roll does not use the standard Very High Skills rule (i.e the halving feature).

As this has not been confirmed by Mr Sprange, I will add a checkbox to my page that dictates whether or not to use this ruling so you can check both ways.

I also missed out the fact that Automatic Failure is reduced for high skills so I'll add that in.

Expect a version 1.0.3 of my MRQPC later today.

In light of a couple of comments on the board (not on this thread) I'd like to say that I'm a big fan of RuneQuest and Mongoose products and I've been looking forward to this game for a while now. I certainly haven't written the MRQPC gadget to 'bash' the game in any way, merely to satisfy my own statistical curiosity; I originally sat down with a piece of paper, then decided to do it in Excel then just realised it would be easier to write it out 'in code'. I'm working straight out of my copy of the rulebook as well and not basing my calculations on rumours from the boards.

 

[bluejay]

Newest version of this is now up. It now includes a checkbox if you wish to use the High Skills Rule for the Opposed Test in combat. It also takes into account the chance of automatic failure reducing as the skills get higher (also this includes the chance of fumble disappearing over 500%).

 

[bluejay]

Another new version uploaded, this one now will also generate stats for Opposed Tests.

 

[janoll]

Another new version uploaded, this one now will also generate stats for Opposed Tests.

Is it my imagination or are the stats flattening out at above 100% with the new version, and using the high skill roll? If so this is better than before and speaks well for the system.

Thoughts?