Surprise attack bonus

[War4ever]

after reading the confusion earlier, i wondered if the ai got a sneak attack bonus again and again against the human player, especially since it almost always wins... not that it picks a tough target usually....

but this isn't the bonus were talking about.....

simply put, first contact , no peace, attack first, get the sneak attack bonus, win against a unit you would not likely beat.... surely this is testable?????

[rah]

Originally posted by War4ever
after reading the confusion earlier, i wondered if the ai got a sneak attack bonus again and again against the human player, especially since it almost always wins... not that it picks a tough target usually....

but this isn't the bonus were talking about.....

simply put, first contact , no peace, attack first, get the sneak attack bonus, win against a unit you would not likely beat.... surely this is testable?????

We are talking about the same bonus. It's just that in our games, we don't make peace then sneak again, so we only experience it once with each player. I would expect to get the bonus every time there is a sneak attack.

[War4ever]

hm, i can't remember the last time we had peace in our games either, i wonder if there were multiple sneak attack bonuses then.....

do you remember the golden days rah?

[rah]

I'm betting that the AI gets the sneak attack bonus every time it breaks a treaty against a human, since it's such a popular thing for it to do.

[Elephant]

If it is just breaking peace treaties we should have seen it before, unless it is only AI-on-human. If it is "first contact" only, that would limit how often we see it, but I take it from the discussion that others have seen it at later stages. Perhaps it is one of those extra things the AI can pull off in Deity games, like getting a WoW one turn after getting the tech...

[War4ever]

well the ai has the ability to combine all its shields working on wonders IIRC so the one turn wonder isn't so hard for it to do in the later stages....

i also wonder if the ai can buy shilds at a 1-1 pace?

[rah]

War4, since no one seems to be jumping up to volunteer to test it and it take two to test it in MP, I propose that we do it prior to one of our normal weekend games while we're waiting for people to show up. Give us a chance to contribute to the strat community.

[rah]

darn nonresponding site, DP Honest.

[Scouse Gits]

Originally posted by rah
War4, since no one seems to be jumping up to volunteer to test it and it take two to test it in MP, I propose that we do it prior to one of our normal weekend games while we're waiting for people to show up. Give us a chance to contribute to the strat community.

That would be great, rah -- finally lay one of the urban myths (or features of the game) to rest...

SG[1]

[rah]

Yep. And considering how much effort others have done while I sat back and kibitzed, it's probably time that I stepped up to the plate and participated in the drugde of testing. Due to the nature of the amount of time it takes to restart an MP game, I probably won't run hundreds of tests, but I'll check with my stat boys to find out how many I need to do to prove it at a high confidence level. (95%)

But I will only test human against human, I'll leave AI to human to someone else, even though I believe the results would be the same.

RAH

[DrSpike]

Originally posted by rah
I'll check with my stat boys to find out how many I need to do to prove it at a high confidence level. (95%)

RAH

Perhaps I can help. You are essentially testing a null of 'no bonus' against a alternative of 'there is a bonus'. The exact calculations are tricky, because combat results are a hypergeometric binomial random variable, and because the exact 'power' of the test depends on an exact specification for the alternative hypothesis. However for the first problem the exact formula is in the combat info thread. The second I explain below.

You see your question is badly formed. The probability of rejecting the null when it is true will be fixed by the experimenter......it tells nothing. The probability of accepting the null when it is false depends on the exact specification of the alternative hypothesis.

Since the proportion of 'successes' in repeated binomial trials is normally distributed (and the variance can be derived as a function of the probability of individual success and the number of repititions) you can derive a decision rule consistent with a probability of incorrectly rejecting the null of 5%.

Of course when people do these civ tests usually they overkill the problem, because the number of tests is explicitly included in the decision rule.

The conclusion is you just need enough repititions to yield an acceptable power......and ensure that the proportion is normally distributed as assumed. Use 50.......you definitely need more than 30. Any more than 50 is overkill.

[Scouse Gits]

Hypergeometric Binomial Random Variate - I thought I was the mathematician around here - but in fairness not a statistician...

SG[1]

[DrSpike]

I didn't make it up honest.

*whispers* all it means it that combat is the result of several rounds of fighting.......but they aren't independent repititions.

Everyone uses the shortcut instead, but if Rah wants to do the test properly (and hence save himself a few hundred repititions) he will need to know the exact probabilities.

[rjmatsleepers]

Originally posted by DrSpike
I didn't make it up honest.

*whispers* all it means it that combat is the result of several rounds of fighting.......but they aren't independent repititions.

Surely the rounds are independent. The probability of winning a particular round depends on the attacker's attack strength and the defender's defence strength (with any modifications - veteran, terrain, etc). Neither of these change during the contest. Similarly the damage does not change during the battle. So the probability of a given attacker beating a given defender is fixed and can be calculated by using a binomial distribution of round results and summing those that give a victory. Once the probability of winning a contest is known, the number of wins in a trial of a known length is again binomial.

For as few as 25 trials, the 95% confidence intervals around the expected number number of wins with a zero and a 50% bonus don't overlap. So the 50% sneak attack bonus can be tested relatively quickly. Incidentally, my tests using SP confirm other people's results that there is no 50% bonus for an attack by the human player that breaks a treaty compared with the same attack during a war.

RJM at Sleepers

[DrSpike]

Originally posted by rjmatsleepers

Once the probability of winning a contest is known, the number of wins in a trial of a known length is again binomial.

Sorry but it isn't.

I am not going to prove it here (it requires moment generating functions, which are some rather nasty albeit incredibly useful mathematical tools) but I can post a reference or PM you if you have any questions.