Bonus Cache

[+Jayeffel]

I just saw the Bonus Cache attribute, I'm not sure I heard of them before. What exactly constitutes a Bonus Cache?

[+MartyBartfast]

https://www.geocaching.com/help/index.php?pg=kb.chapter&id=127&pgid=927

[+Jayeffel]

4 hours ago, MartyBartfast said:

https://www.geocaching.com/help/index.php?pg=kb.chapter&id=127&pgid=927

I just found that, it sounds like the cache I have started but not placed yet. It describes a cache but is not seperate type like Traditional, mystery, multi, etc. 

Edited September 7, 2020 by Jayeffel
punctuation

[+Max and 99]

Just fyi, according to the help center, bonus caches are always listed as a mystery cache type.

 

A bonus cache is a Mystery Cache for which you have to find clues in other caches. Sometimes the coordinates for the bonus cache are in one other cache. In other cases, you gather clues for the final coordinates of the bonus cache from multiple other caches. Clues for a bonus cache can be hidden in any other cache type.

Edited September 7, 2020 by Max and 99

[Darwin473]

3 hours ago, Max and 99 said:

A bonus cache is a Mystery Cache...

 

Can you have an unlisted bonus cache? So caches A, B and C have the clues on where to find X, but X is just a container, logbook, swaps etc with no digital page?

 

Does the bonus cache have to be within an achievable distance of the clue caches? Meaning, could you have the clue caches all located on the mainland, and the mystery cache located on a random sandbar in the middle of the ocean?

[+barefootjeff]

35 minutes ago, Unit473L said:

Can you have an unlisted bonus cache? So caches A, B and C have the clues on where to find X, but X is just a container, logbook, swaps etc with no digital page?

 

There's nothing to stop you from doing that, but nobody would get a smiley for finding the unlisted bonus or be able to log it.

 

36 minutes ago, Unit473L said:

Does the bonus cache have to be within an achievable distance of the clue caches? Meaning, could you have the clue caches all located on the mainland, and the mystery cache located on a random sandbar in the middle of the ocean?

 

Since the bonus is a physical cache, it has to be within maintenance reach of the CO, so unless the CO lived on that sandbar in the middle of the ocean, probably not. But I'm not aware of any specific distance limits between the clues and the bonus. Not unlike a multi whose virtual waypoints can be scattered far and wide.

[+cerberus1]

54 minutes ago, Unit473L said:

Can you have an unlisted bonus cache? So caches A, B and C have the clues on where to find X, but X is just a container, logbook, swaps etc with no digital page?

 

We've seen that years ago, not so much today.  I think when most realized that everyone was missing out on another smiley, that changed.  

A couple "competition" events had a "bonus", with coordinates created on puzzle cards showing where your prizes were.

 

[+Jayeffel]

3 hours ago, Unit473L said:

 

Can you have an unlisted bonus cache? So caches A, B and C have the clues on where to find X, but X is just a container, logbook, swaps etc with no digital page?

 

Does the bonus cache have to be within an achievable distance of the clue caches? Meaning, could you have the clue caches all located on the mainland, and the mystery cache located on a random sandbar in the middle of the ocean?

That is what I was considering;  decided to go with multi-cache with two container, the first is at a definite coordinate spot and gives direction to the second stage, which is not very far from where the cacher will park, so in a sense finishing where he starts almost. The cacher will not know that until stage one is found. The log is in the second container.

Edited September 7, 2020 by Jayeffel
spelling

[Darwin473]

Ah, right. Well that all clears things up. I must have been confusing Mystery with Virtual in my head. I'll go back under my rock now.  

[+Max and 99]

9 minutes ago, P@T@ said:

What Is your opinion to D/T rate of bonus cache ? Should be like the highest combinatoin of all caches from serie or not ?

E.G. 5 traditional caches with different Terrrain rate from T1 to T5, all of them contain part of final location of bonus cache => that means the bonus cache should be T5 although locklock box laid in a wheelchair zone ?

I'm my area, the D reflects the difficulty collecting all the required information/clues. The T reflects the terrain of the actual bonus cache hide. 

[+ecanderson]

I'd be inclined to award difficulty points for the higher of the previous caches, leave the terrain appropriate to the actual bonus cache, and make a note in the description that the difficulty is based upon the most difficult cache in the prior series.

 

I treat them like a multi.  Difficulty for the cache is for most difficult stage, which is only fair, but final description identifies the actual difficulty of the final.

Ditto puzzles.  You get your difficulty based upon the more difficult of the puzzle or the actual find, but the final describes which is which.

 

[+ecanderson]

7 minutes ago, P@T@ said:

But the whellchair user Is not able to get the bonus cache without visit T5 part of series...

If someone in a wheelchair can't do the series, then the final shouldn't be rated 1.0, it should be rated 1.5 if on flat, level ground.

[+ecanderson]

True, but you provided an exceptional case, and that's how it could be handled.  Of course, if there is really no way to solve the previous caches from a rollie, then the point is moot since those folks won't be getting the information necessary to find your bonus anyway.

In a way it's no different than a multi where one stage somewhere ahead of the final isn't WC accessible.  You couldn't rate the final a 1.0 under any circumstances then, either.  Same rationale.

[+ecanderson]

18 minutes ago, P@T@ said:

My questin pointing to AL - they dont have D/T rate, if one (or more) of lab stage lay too high, the bonus T rate should reflect, although it lays at the ground level.

Yes.  I would apply the same principle.  Rate a bonus cache's terrain for the highest terrain situation a finder must overcome in the whole series.  That will give people with less physical ability some idea of what they're getting into.

[+barefootjeff]

1 hour ago, P@T@ said:

But the whellchair user Is not able to get the bonus cache without visit T5 part of series...

 

Yes they can if someone else provides the information for them, a partner or friend perhaps. I think the T rating of the bonus should be just that of the bonus cache so those going for that cache know what to expect and what equipment they might need. Even if one of the feeder caches needs a boat, there's no point carting one along to the bonus if that itself doesn't need it.

[+thebruce0]

This is the same issue for why we have 5/5 Challenge caches that are LPCs.  Differing opinions about how the D and T apply, whether to the cache itself or the minimum requirements among any of the tasks needed to complete prior to and in order to log as found.

I think this is one where there isn't a "this is how you do it" rule, but as a geocache finder, a good habit is just to read everything about the cache if you're uncertain, and as a cache owner, explain the reasoning where it's not readily apparent.

[Keystone]

The analogy to challenge caches is a good one.  There, we have guidance from Geocaching HQ:  "We recommend that the difficulty rating be based on the challenge, the terrain rating on the challenge cache location."  

[+niraD]

6 minutes ago, P@T@ said:

New attribute for bonus cache is good idea, but maybe would be better to have new type of cache for bonus cache & exact rules for it.

Now that there's an attribute, I doubt you'll get a new type for bonus caches. But there are rules for them in the Help Center: Bonus caches

[+niraD]

23 minutes ago, P@T@ said:

I know the rules for bonus cache. Don't feel the difference between plain mystery cache and bonus cache? For the bonus you must "usually" do more. As well as to meet the challenge.

I thought the first sentence of the Help Center article explained the distinction pretty well:

"A bonus cache is a Mystery Cache for which you have to find clues in other caches."

[+ecanderson]

2 hours ago, Keystone said:

The analogy to challenge caches is a good one.  There, we have guidance from Geocaching HQ:  "We recommend that the difficulty rating be based on the challenge, the terrain rating on the challenge cache location."  

Would you make an exception for 1.0/1.5 since 1.0 would seem to infer that all prior waypoints are equally accessible?  That would avoid picking up a 1.0 in a filter that wasn't actually possible due to prior waypoints being inaccessible.

[+The Jester]

5 hours ago, P@T@ said:

I know the rules for bonus cache. Don't feel the difference between plain mystery cache and bonus cache? For the bonus you must "usually" do more. As well as to meet the challenge.

What is a "plain mystery cache"?  The mystery type is a 'catch-all' for caches that don't fit other types - puzzles, Challenge Caches, and bonus caches are parts (but not all) of the type "Mystery".

 

[+ecanderson]

Perhaps calling it a "solo" mystery cache would have helped ... one that is not involved with any other cache or ALC.

 

[+colleda]

10 hours ago, P@T@ said:

Maybe rules for bonus caches should be set. The placement of the bonus cache in the field must correspond to the most difficult terrain in the series...

Disagree. A T rating based on any number of other caches is misleading. The bonus could be quite easy to find but some may be put off looking for it due to the Terrain rating.

[+cerberus1]

10 hours ago, P@T@ said:

Maybe rules for bonus caches should be set. The placement of the bonus cache in the field must correspond to the most difficult terrain in the series...

2 minutes ago, colleda said:

Disagree. A T rating based on any number of other caches is misleading. The bonus could be quite easy to find but some may be put off looking for it due to the Terrain rating.

 

Yep. 

Just like the majority of multis finals in this area, most "bonus" caches we've ever found were on the way back to the car, in a low-terrain spot.   

[+ecanderson]

44 minutes ago, colleda said:

Disagree. A T rating based on any number of other caches is misleading. The bonus could be quite easy to find but some may be put off looking for it due to the Terrain rating.

But if it is an Adventure Lab bonus (I think that's where the OP was heading with all of this), there are no terrain ratings to see for the AL stages in advance, and someone with limited ability (or interest) to deal with a set of high terrain AL stages would then know if the series and bonus cache are worth pursuing.  At a minimum, I would think as noted before that with gc.com's goofy 1.0/1.5 change many years back, a bonus cache shouldn't be rated 1.0 unless the ALs that must be accomplished ahead of it are all 1.0 as well.  If not, give the bonus cache a 1.5 for filtering purposes.  Frankly, I prefer the attribute to have been the determining factor for filtering instead of the 1.0 terrain (I find them redundant), but I didn't get to vote.

Edited September 9, 2020 by ecanderson

[+thebruce0]

If a CO wants to make known what the D/T is for the AL, the best place to do that is in the AL description, not the bonus cache properties. The bonus ratings should be relevant to the bonus cache. Additionally, they could state in the bonus cache description what the D/T of the associated Adventure Lab would be, much like challenge cache owners do for the cache D/T if instead of they rated the DT for the challenge and not just the cache itself. Again this is because of the overlapping properties of more than just the single "find and sign" task for a regular geocache.

 

I think the best rule of thumb for any cache type is to keep the D and T relevant to the listing.  T is always going to be relevant to the cache in question. D should be relevant to the task required to be able to claim the find (challenge difficulty, or D of the AL, or prerequisite cache series, or puzzle, etc, while of course including any additional direct camouflage or cache-finding difficulty).

#opinion

[+The Jester]

5 hours ago, P@T@ said:

The "plain mystery cache" = usual unknown cache, with some cipher or puzzle to solve, without depending on other caches. Or can say without any new attribute (bonus or challenge). At geocaching map there are too many mystery caches, difficult to recognize which of them depends on "special" condition. My opinion is, that will be helped if these two "special" mystery caches get own icon and colour. Quick look at map then says what cache it is.

What you describe is a common (maybe the most common) Mystery Cache, the puzzle cache.  But that is not all the Mystery Cache type is.  Even field puzzles is a subset that doesn't have anything to solve before finding the cache.  MC's also can include very odd containers that don't match the size chart (i.e.. a very large object with a micro interior).  Don't fall into the trap of 'the most common usage is the only usage'.

[Darwin473]

4 hours ago, The Jester said:

Even field puzzles is a subset that...

 

Do gadget caches fall into the Mystery Cache category? Or are they considered a Traditional with the description saying "this is a gadget cache..."?

[+on4bam]

42 minutes ago, Unit473L said:

 

Do gadget caches fall into the Mystery Cache category? Or are they considered a Traditional with the description saying "this is a gadget cache..."?

Depends.

Traditional + "field puzzle" attribute should cover it unless the cache is not at the posted coordinates.

Of course, a gadget cache may be better "protected" if listed as a mystery and/or PM only + higher D rating. As always, reading the listing is a good start.

 

[+ecanderson]

13 hours ago, thebruce0 said:

I think the best rule of thumb for any cache type is to keep the D and T relevant to the listing.  T is always going to be relevant to the cache in question.

#opinion

So if the final of a multi is at the base of a tree, and you have to climb 5 trees to get forward coordinates to get to the final, the terrain should then be 1.5 for the physical final?  Seems to be the same problem to me.  You really can't win either way.  It's up to the owner to make clear what's happening in the text that accompanies the cache/AL, but if the objective is to provide good information for search purposes (e.g., cacher physically not up for T of more than 3.0), then the whole thing would have to be incorporated into the single T available, the one that appears in the listing.

 

Edited September 10, 2020 by ecanderson

[+thebruce0]

25 minutes ago, ecanderson said:

So if the final of a multi is at the base of a tree, and you have to climb 5 trees to get forward coordinates to get to the final, the terrain should then be 1.5 for the physical final?

No. Because it's a single multi-cache listing, not a standard geocache at the base of the tree that's a bonus to a bunch of other cache listings.

[+ecanderson]

29 minutes ago, thebruce0 said:

No. Because it's a single multi-cache listing, not a standard geocache at the base of the tree that's a bonus to a bunch of other cache listings.

You don't see an analogous situation here?  In both cases, it is expected that one series of finds proceeds a final.  The multi-cache listing can either incorporate T levels from all stages or not.  With an AL and a bonus, the bonus can either incorporate T levels from all stages or not.  From a practical standpoint (searching based upon T level), I don't see any difference.  Yes, all else can be managed via the text in either a multi or an AL+bonus, but if users are searching based upon T levels, the problem is identical.

[+thebruce0]

Just now, ecanderson said:

You don't see an analogous situation here?  In both cases, it is expected that one series of finds proceeds a final.

In one case it's all contained in one listing. In the other case(s) it's separate listings.

 

Just now, ecanderson said:

The multi-cache listing can either incorporate T levels from all stages or not.

Most people I think would agree that the Multi listing's D and T would encompass all of the inherent stages, for that single geocache find. eg I've never seen a multi listing underrated for requirements at one stage.

A bonus cache is a separate listing. An Adventure Lab is a separate listing (though without relevant properties, but with a description).

 

Just because numerous listings are related doesn't mean their properties all need to be relevant to each other.

The difference for certain Mystery caches is that the requirement to log online (not the terrain) IS related to an additional intended task - be it qualify for a challenge, find other geocaches, or complete an Adventure Lab. I say not the terrain because the terrain only gets you to the cache itself, the relevant listing. You can open it and sign it, and the terrain is done. But the difficulty is different in that merely signing doesn't allow you log it online, at least by CO's intention.  Apart from brain use or local camouflage of the container, Difficulty can relate to that challenge ALR, or those additional tasks.

 

If I had a series of 2/2 traditionals plus a bonus cache in a tree, I might rate the bonus a 1/4; maybe a 2/4.  If they were all 5/5 caches in the series, and the bonus was an LPC, I'd likely rate it 5/1, because the intended difficulty of completing the series is certainly worthy of the 5, and the terrain needed to sign the log is 1.0. I'd say the benefit of separate listings is that there are more places to put relevant details; why duplicate ratings merely because they're related?

 

If I had a multi where stage 1 was a 5/5 and the final was a 1/1, the Multi listing would be rated 5/5, because it's one listing.

If I had an Adventure Lab that's effectively a 1/1 providing info for the bonus cache that's on an island, I'd likely rate the bonus 1/5.

Or vice versa, if the Adventure Lab had a stage that required special equipment to get the info, and the bonus was an LPC, I'd describe what'll be needed it in the AL listing, and I'd likely rate the bonus maybe 4/1, where the D is related to the difficulty of completing the intended task - the Adventure Lab.

 

That's at least how I'd break it down... #opinion

[+BreezynBlackDog]

Hi Everyone, I tried to read this thread but is getting way too technical for me.

Bottom line, if I want to add bonus cache to my existing cache, how does it get registered? Do the distance rules still apply?

Thanks

[Keystone]

3 minutes ago, BreezynBlackDog said:

Hi Everyone, I tried to read this thread but is getting way too technical for me.

Bottom line, if I want to add bonus cache to my existing cache, how does it get registered? Do the distance rules still apply?

Thanks

1.  Setup a new cache page as a Mystery Cache with the Bonus Cache attribute. 

2. The cache page should explain that the clue for your Bonus Cache can be found in your existing cache.

3.  Your bonus cache must be at least 528 feet away from any other cache, including your existing cache upon which it is dependent.

4.  Edit your existing cache page to tell visitors that there is a clue for a bonus cache inside of the existing cache.  And, visit your cache to place the clue.

5.  Submit your new Mystery Cache for review.

[+Ninemm]

This thread answered most of my questions, but one. (And I think I know the answer.)

I’m planning a series of nine simple mystery caches all around our county. The puzzles are not difficult, and are probable good for introducing new cachers and older children to mystery puzzles. 
I realized it might be nice to have a tenth, for those who found the entire series. Each cache could have part of the solution. 
 

My question is:

This tenth cache would be a bonus, mystery cache?

And the physical, final location would have to be within two miles of the posted coordinates?

I’m guessing yes, like any other mystery cache. 

[+niraD]

1 hour ago, Ninemm said:

This tenth cache would be a bonus, mystery cache?

And the physical, final location would have to be within two miles of the posted coordinates?

I’m guessing yes, like any other mystery cache. 

Exactly. The bonus cache is a mystery/puzzle cache, regardless of the type(s) of the 9 caches in the series. And like any other mystery/puzzle cache, the final cache has to be within 2 miles of its posted coordinates.

I've seen complicated formulas used to generate the final coordinates of bonus caches. Often, bonus caches can be found with only part of the information if the formulas aren't created carefully. The best way I've seen to do it is simply to put a number several digits long in each cache in the series, and add all those numbers to get the digits of the final coordinates. If the numbers in the series caches are very different from each other, then it's hard to guess what the missing number(s) might be. Usually, the numbers add up to a 6 digit number (filling in N 36° 15.ABC W 082° 10.DEF, for example), or an 8 digit number (filling in N 36° 1A.BCD W 082° 1E.FGH, for example).

 

And don't forget the Bonus caches article in the Help Center.

[+thebruce0]

Adding numbers is one of the easiest ways to obfuscate the answer, but regardless of the number of digits there's still a potential certainty growth from the most significant digits to the least significants.  ie, find 8 of 9 caches and there's a much better chance of 'guessing' the answer.  Usually it's plenty for the vast majority of people to make an easily protected answer.

One way to ensure universal uncertainty of every digit in the answer is to use a form of hash, where any new element to the cipher changes every digit equally randomly (effectively). Then the only way to get the answer is to have and use every element that composes the cipher; miss any component, and result is equally seemingly random.

 

I've found the easiest way to do this is to use the XOR function.  If there are 5 numbers plus the answer, if you XOR all values you have together, then you will only result in the answer once all 5 of the other values have been XOR'd together, no matter the order. It'd be best to link to a tool that does it easily (try explaining how it works, heh)...

It's like completing a circuit that lights up when all but one piece is connected; until it's complete the shape of the last piece remains obfuscated.

Or, you could think of it like you can only figure out the size of the first piece of pie that was taken if you can determine the size of everything taken that wasn't that first piece of pie.

Or something like that

 

Setup:

Each cache in the series reveals a number.  The solution for the bonus could be the 6 digits of the coordinates.  XOR all the series cache numbers together and the result will be the bonus number needed.

 

If you're creating it, you'd take the bonus solution number first, then XOR number 1 found in cache 1; then XOR the result with number 2 found in cache 2; then XOR the result with number 3, and so on. The last result number is placed in the last cache of the series. Then, it doesn't matter which order the caches are found, but every number must be XOR'd before the bonus cache solution number is revealed:

Bonus cache, number AAAAAA solution

Cache 1 holds any number BBBBBB (xor AAAAAA = XXXXXX)

Cache 2 holds any number CCCCCC (xor XXXXXX = YYYYYY)

Cache 3 holds any number DDDDDD (xor YYYYYY = EEEEEE)

Cache 4 holds number EEEEEE

 

Then AAAAAA is only found as BBBBBB xor CCCCCC xor DDDDDD xor EEEEEE (in any particular order)

 

It's a complicated system to explain, but simple to implement and evaluate, as long as there's a tool to do it for the layperson.

(personally I'd work it with binary numbers as xor is much easier to visualize and understand with binary digits)

[+fuzziebear3]

Yes, you can cipher it or whatnot.   But actually I am okay if people figure out / guess at one or more of the digits.  They solved the puzzle one way or another.  Around here, the typical approach is to put one number in each cache, like A=6, B=9, C=7, D=3, E=8, F=5, where the coordinates are in the form 39 39.ABC 84 08.DEF, or similarly. 

 

Cachers usually find all in the series anyway, because they want to, and because it is not known which digit might be in which caches.

 

No need to overcomplicate it -- it is not really a competition

 

 

 

[+thebruce0]

49 minutes ago, fuzziebear3 said:

No need to overcomplicate it -- it is not really a competition

I know, I was just explaining an option for people who want to ensure guessing early isn't possible, or at least not worth their while; Doesn't mean it's a competition

 

Most COs go with the option of the X=# method, but again those can be guessed, sometimes as early as finding 2 of 6 caches in a series, depending on how much time someone is willing to put into trial and error guessing (especially with a coordinate checker). Most don't care, some do. That's all  

[+dprovan]

1 hour ago, thebruce0 said:

I know, I was just explaining an option for people who want to ensure guessing early isn't possible, or at least not worth their while; Doesn't mean it's a competition

Yes, but in this case, since the entire series is intended as an intro to puzzles, I'd err in the way that makes it more likely for people to be able to locate the tenth cache even if they can't solve one or two of the puzzles. In fact, for any bonus cache, I prefer the approach that allows a logical guess since it's quite common for one or two of the final caches go missing in a series like this.

 

But if one does want to require all nine caches be found first, I'd avoid any kind of complicated hashing approach and have each cache provide a keyword, then just require all the keywords to be strung together and passed to a checker such as certitude. Or the nine keywords could be the basis for a 10th puzzle, if you prefer. The only time I'd even consider any kind of XOR hashing is if the final location has to be calculated in the field away from any network. That doesn't sound like the case here, but if it were, then the guess the ninth digit hack to get around finding all nine caches becomes much less of a problem, anyway.

[+thebruce0]

8 minutes ago, dprovan said:

Yes, but in this case, since the entire series is intended as an intro to puzzles, I'd err in the way that makes it more likely for people to be able to locate the tenth cache even if they can't solve one or two of the puzzles. In fact, for any bonus cache, I prefer the approach that allows a logical guess since it's quite common for one or two of the final caches go missing in a series like this.

Yep, there are many options available to a cache owner who wants to make a series with a bonus cache.

 

8 minutes ago, dprovan said:

But if one does want to require all nine caches be found first, I'd avoid any kind of complicated hashing approach and have each cache provide a keyword, then just require all the keywords to be strung together and passed to a checker such as certitude.

Using a geochecker is another option, where no part of the bonus solution is knowable until the final keyphrase is provided. Yep.

 

I was responding to the use of coordinate placeholders - a strategy where each cache provides some element of the final coordinates, encoded or not. In that case, the "complicated" (to explain, not use) strategy is one available to a cache owner who does want all caches in a series to be found first, with as little chance of guessing or 'ubering' as possible.  One of many options.

[+niraD]

5 hours ago, thebruce0 said:

Adding numbers is one of the easiest ways to obfuscate the answer, but regardless of the number of digits there's still a potential certainty growth from the most significant digits to the least significants.  ie, find 8 of 9 caches and there's a much better chance of 'guessing' the answer. 

I'm still trying to figure out how someone could guess a location based on the missing numbers, for something like this:

 

Formula: N 36° 15.ABC W 082° 10.DEF

 

Add numbers found in 9 different series caches to get ABCDEF, where the numbers are:

 

77526 +

132203 +

97868 +

45743 +

79323 +

47542 +

199540 +

56769 +

37706 =

ABCDEF = 774220

 

Final: N 36° 15.774 W 082° 10.220

[+barefootjeff]

4 hours ago, fuzziebear3 said:

Yes, you can cipher it or whatnot.   But actually I am okay if people figure out / guess at one or more of the digits.  They solved the puzzle one way or another.  Around here, the typical approach is to put one number in each cache, like A=6, B=9, C=7, D=3, E=8, F=5, where the coordinates are in the form 39 39.ABC 84 08.DEF, or similarly. 

 

Cachers usually find all in the series anyway, because they want to, and because it is not known which digit might be in which caches.

 

No need to overcomplicate it -- it is not really a competition

 

Something else to bear in mind is that most cachers, after finding the caches in the series, will be wanting to work out the coordinates on the spot and go straight for the bonus without going home first, so anything that requires complex calculations or has to be done online could be problematic for some. Best if it's something that can be easily solved with pen and paper.

[+thebruce0]

39 minutes ago, niraD said:

I'm still trying to figure out how someone could guess a location based on the missing numbers, for something like this:

Statistically, there's more uncertainty on the least significant digits than the most. In your example, f you're only adding to attain ABCDEF, then as the higher digits increase, there are fewer to guess. The north coordinate will have more likely options before the west component, and a determined cacher can view the map and reduce options.  I've done this before, as have others I know of. Trust me, if it can be done, and the cacher feels it's worth the effort, they will =P

Edited April 21, 2022 by thebruce0

[+Wet Pancake Touring Club]

I found a bonus cache once, where there were nine cache in a series, each cache had one digit of the bonus cache coordinates. Those digits were in order, four for the N/S position, and five for the E/W coordinate. Cache #8 was missing. So, I had the coordinates, except for the second to last digit of the E/W coordinates. On my GPS, I plugged in the coordinates, using a zero for the missing digit, and went to that location. From there, I plugged in a 9, and walked towards that point. It was a very short distance between those two points. And, there were very few hiding locations, as the line I walked was through a large intersection. (Back country roads, no traffic.) Now, if I was missing some of the more significant digits, the line would have been a lot longer. Still, missing any single digit meant I could 'battleship' the bonus cache, there would only be 10 locations where it could be.

[+mustakorppi]

39 minutes ago, thebruce0 said:

Statistically, there's more uncertainty on the least significant digits than the most. In your example, f you're only adding to attain ABCDEF, then as the higher digits increase, there are fewer to guess. The north coordinate will have more likely options before the west component, and a determined cacher can view the map and reduce options.  I've done this before, as have others I know of. Trust me, if it can be done, and the cacher feels it's worth the effort, they will =P

This only works if you’re assuming all the numbers are going to be positive  Or the CO could make it FEDCBA instead of ABCDEF. I think the main point is that simple addition is, perhaps counterintuitively, better for this than complex formulas with multiplication and so on.
 

Of course sometimes the surrounding geography, saturation, D/T and attributes give so much away that the cache can be brute forced just with just that.

[+thebruce0]

6 hours ago, mustakorppi said:

This only works if you’re assuming all the numbers are going to be positive  Or the CO could make it FEDCBA instead of ABCDEF.

As I said, there are many ways a CO can attempt to obfuscate the answer. If adding but it's flipped FEDCBA then the most significant digit is the rightmost; same points apply.  My example - just one method - was meant to highlight how obfuscating each digit equally while requiring every piece to be recovered before a solution can be attained, could be done. Other ways, which provide an element of the solution directly within each piece found, have a statistically greater chance of the solution being battleshipped/ubered/reverse-engineered/guessed, dependent upon how much effort the person feels it's worth. 

 

7 hours ago, mustakorppi said:

I think the main point is that simple addition is, perhaps counterintuitively, better for this than complex formulas with multiplication and so on.

That would depend on the CO of course, but another benefit of xor is that it's not a math problem you need to do in your head, or figure out algorithmically. As mentioned, if the tool is provided, it's as simple as "find all the values, pipe them through the tool, get the answer" and you don't have to understand how or why it works, just that it does.

 

7 hours ago, mustakorppi said:

Of course sometimes the surrounding geography, saturation, D/T and attributes give so much away that the cache can be brute forced just with just that.

Absolutely. There's no guaranteed way to get a cacher to do exactly what the owner wants them to do.  There's only a variety of methods and strategies the CO has to weigh, and decide what aspect of the geocaching experience is most important to what they want to provide anyone who targets their caches.

 

Whether to find the bonus you need to find and add 6 numbers, multiply, xor, or string together keywords, average waypoints, whatever...  They all have strengths and weaknesses, and all are equally valid strategies. The more options we can be aware of to consider, the more versatility we have as owners to shape the experience we want to provide.

 

If you really want to provide that strict experience of requiring finding each element of the puzzle hidden in a series of geocaches before finding the "final", (and dissuade "cheaters") then the best chance of that is a method that makes it the least statistically likely to guess or calculate the answer.  That can only be where either no part of the solution is included in the pieces to find, or no piece to find lets you see progressively more of the solution - that means a geochecker with whatever compiled final phrase must be submitted, or a hash-style piece-puzzle that could be embodied in a series of values to be xor'd.  There may of course be other options toward that goal... or, if the CO doesn't want it to be that strict, then merely getting numbers from each cache may be sufficient despite being statistically easier to 'guess' the solution.

 

 

These are all things for a cache owner to consider when designing a geocache "series" with final/bonus. I've seen series published all across this spectrum, and been faced with deciding whether to do some as intended or just uber the final in some way. So all this -- I'm just speaking from observation and experience, both finding and hiding, in my region.

[+mustakorppi]

I agree with your points in general. But because I'm me and you're you, of course there must be nitpicking

 

16 minutes ago, thebruce0 said:

If adding but it's flipped FEDCBA then the most significant digit is the rightmost; same points apply.

The difference is that with ABCDEF (using the numbers above), even in the worst case scenario you know A is at least 5 before finding the last number. Depending on the order you might know it's at least 7. But with FEDCBA, you don't know anything about A until you have all the numbers. And unless you can do the final solve on a non rate limited checker, knowing [7-9][0-9][0-9] is worth a lot more than knowing [0-9][0-9][7-9].

 

40 minutes ago, thebruce0 said:

That would depend on the CO of course, but another benefit of xor is that it's not a math problem you need to do in your head, or figure out algorithmically. As mentioned, if the tool is provided, it's as simple as "find all the values, pipe them through the tool, get the answer" and you don't have to understand how or why it works, just that it does.

I can understand why xor would appeal to a certain type of person   but honestly I would just use a 3rd party checker at that point. Equally safe from brute forcing the solution, no problem linking to it directly from the description, less chance of finder making a mistake with a tool they don't understand, the finder gets verification that their solution is correct, and the CO can give additional hints about parking etc. in the completion message...

[+lee737]

4 hours ago, thebruce0 said:

My example - just one method - was meant to highlight how obfuscating each digit equally while requiring every piece to be recovered before a solution can be attained, could be done.

I'd be inclined to go the other way a touch - ie, allow a find if one was missing..... just give them the checksum of the digits they are chasing, that way a missing one can be calculated, and they can find the bonus, even if they DNF one, or one is missing.... Another way I've seen is to have 2 numbers in each cache, so that each number needed is on the trail twice - this will give even more redundancy in case of missing caches. I suppose it depends on what you are after....