Source
r/IdleMinerTycoon•
ReflexMan

Question about mine shaft economics

QUESTION

Sorry if this has been asked, but I did a bit of googling and looked through a few pages on this subreddit without finding what I am looking for.

Can anyone explain to me why Mine Shaft 11 isn't the most economical? I have seen some people say that it is absolutely the case that each group of 5 mine shafts are leaps and bounds better than anything below, to the extent where you basically shouldn't even buy any levels in any mine shaft before the last barrier you unlocked, because everything after is just so much better. But I have not found that to be the case.

In my experience, at any point in time, if I look at the increase in cash per second for leveling up any shaft once versus the cost of upgrading that shaft once, Mine Shaft 11 will have the best ratio. Sometimes, this means that leveling up the highest mine shaft available will give me more cash per second than leveling up Mine Shaft 11, but at so much more of a cost that the ratio is worse. For example, It might be 1 Trillion cash to level up Mine Shaft 20, and the increase in cash per second is 1 Million, and it might be 100 Billion cash to level up Mine Shaft 1, and the increase in cash per second is 500 Thousand. So leveling up Mine Shaft 20 results in 2 times as much cash per second as leveling up Mine Shaft 11, but it costs 10 times as much, so it's still not as good as Mine Shaft 11. Other times, it's just less to begin with. So it might be 1 Trillion cash to level up Mine Shaft 20, and the increase in cash per second is 1 Million, and it might be 500 Billion cash to level up Mine Shaft 11, and the increase in cash per second is 2 Million. So it's both cheaper AND better to level up Mine Shaft 11.

I have never once looked and seen that the ratio of cash-per-second increase to cost is better for any mine shaft when compared to Mine Shaft 11.

So is Mine Shaft 11 just the best for whatever reason? Or is there some reason why it isn't as economical as I think it is.

It should be noted that the highest mine shaft I have gotten to in any mine is 22 or so. It should also be noted that I understand that at certain levels, there is a huge boost to the production of the mine shaft without any additional large increase in cost. So I know it's possible that either some mine shafts beyond 22 are more economical than 11 (even if everything up to there is worse for some reason). And I know it's possible that a level 150 Mine Shaft 20 might be worse than a level 400-something Mine Shaft 11, and that while it's worse at the time, it's still worth buying more levels of, because the boosts end up making it worth it. But it seems like at any point in time, the cash-rate-gain per cost ratio always favors Mine Shaft 11.

Posted Nov 17, 2017, 1:52 AM UTC

331
lazyguyoncouch•

Every mine is 10 times better than the previous mine. Not sure why people are hung up on 11, it's better to save up for the next mine lower vs upgrading. Even when you reach level 30, upgrade level 30 along with your warehouse and elevator evenly.

3
ReflexManOP•

But why, though. If I can get an additional 1 Million cash per second if I upgrade Mine Shaft 11, and I can get an additional 1.5 Million cash per second if I upgrade Mine Shaft 20, then Mine Shaft 20 seems better. But if Mine Shaft 20 costs 5 times as much, then it isn't better. I am paying more for less when upgrading it. Why is that better?

2
lazyguyoncouch•

How is that not better? You are making more per second. Every 2 seconds you double what you would have been making.

I have all mines unlocked and most to level 30. When I prestige a mine I'll max level 1 to 800 and leave all the rest at 1 except level 30. I'll upgrade level 30 and the warehouse and elevator evenly balancing them out to get the most cash per second. The end goal as with most of these idle cash making games is not to have the most money, it's too have the most income. Invest as much money back into the game to increase your income as fast as you make it. That's how I play anyway and its been working for me.

1
ReflexManOP•

What do you mean, "how is that not better"?

Assume Mine Shaft A will increase your income by 100 cash per second for 1,000 cash. Assume also Mine Shaft B will increase your income by 200 cash per second for 10,000 cash. Yes, buying a level of Mine Shaft B will give you twice as much income as a level of Mine Shaft A. But you could buy several levels of Mine Shaft A before you could buy a single level in Mine Shaft B. If you save up 10,000 cash to get one level in Mine Shaft B for 200 extra cash per second, you could have bought several levels of Mine Shaft A in the mean time and increased your cash per second by much more than 200 per second.

So why is it such a big deal to get more cash per second for a single level of a mine shaft? It seems to make more sense to get the most cash per second per cash you spend. I'd rather buy 10 levels of a mine shaft that is giving me 100 cash per second than 1 level of a mine shaft that is giving me 200 cash per second, because 10100=1,000 is higher than 1200=200.

2
yemgi•

I fully agree with you

1
ReflexManOP•

Care to explain why with math? If you level two mine shafts to the point where each of them costs X cash to level up one more time, then you want to buy a level in the mine shaft which gives more cash per second. It might be the case that Mine Shaft 20 at level 100 is better than Mine Shaft 11 at level 100. But if you have Mine Shaft 20 and Mine Shaft 11 each at a point where the next level costs X cash, Mine Shaft 11 will give more cash per second for that level up than Mine Shaft 20 will. So why would Mine Shaft 20 be better?

1
yemgi•

I agree with your math and that the most cost effective is not always the last shaft. What I meant is that it is usually even more cost efficient to open shafts 21 to 30 than to upgrade shaft 20 or shaft 11.

3
ReflexManOP•

I wish I had ever seen that. But so far, that has never been the case. I regularly upgrade all of the mine shafts I have available such that they are roughly the same price point for the next level. That way I can scan through them and see which will give the most for the next level. Every time, it has been Mine Shaft 11. If every mine shaft I have available costs 1ad-2ad, Mine Shaft 11 will give far more for the next level than any other mine shaft. So I just continue leveling that one primarily.

2
lazyguyoncouch•

Because it's not 2x numbers we are talking about. It's 10x numbers.

2
ReflexManOP•

Yes, and more than 10 times the cost. It doesn't matter if leveling up a mine shaft gives 10 times as much cash per second as some other mine shaft. If it costs MORE than 10 times as much to level up as the other mine shaft, then it is still not as economical.

X / Y > 10X / 20Y

Even though 10x is 10 times as much as X in the numerator, 20Y is 20 times as much as Y in the denominator, so it is still less cash gain per cash. So it's not economical.

1
lazyguyoncouch•

I get what you are saying,but I don't agree with your reasoning. Your original question is about shaft 11 and I'm saying to upgrade the lowest shaft you can. If you want to work it out and split pennies that's on you, I don't have all day to devote to math, it's an idle game. More cash per second on idle is worth more to me than less cash per second but I have more money in the bank. If there was interest it would be a different story.

2
ReflexManOP•

You really just are not understanding my point, then. I am not arguing that it's better to keep more in the bank.

Assume I have some amount of money in the bank. Your goal and my goal are the same. We both want to spend down to 0 to increase the gain per second as much as possible, and then close the app and let it earn. I am saying that according to very simple math, it is more cost-effective to upgrade Mine Shaft 11 as much as I can afford to (and then let the app idle) than to upgrade some higher Mine Shaft as much as I can afford to (and then let the app idle).

You seem to be under the impression that I am saying it's bad to spend more to get more, because having more money on hand is better. That is NOT what I am saying. I am saying that buying 10 levels of a Mine Shaft at X cash per second per level is better than buying 1 level of a different Mine Shaft at 2X cash per second per level. Even though 2X is twice as much as X, the cost is 10 times as much, meaning I can buy 1/10 as many levels, so I end up earning 1/5 as much cash per level.

2
lazyguyoncouch•

To max coal 11 to level 800 would cost me 426aq with a return rate of 263ao

To level up coal 29 once to level 2 would cost me 228ap with a return rate of 464ao

How would maxing out level 11 help when I can level 29 once at 1/2000th the cost and make twice as much?

3
aZubaer•

You are not factoring in that mines get more inefficient the higher their level is - so you are right upgrading mine 11 lvl 1 is more efficient - than upgrading mine 25 lvl 1, But upgrading mine 11 lvl 700 to 701 is less efficient than mine 25 lvl 1, although they have could have similar cost.

2
ReflexManOP•

That might be true, I guess I just haven't gotten to that point. As I explained in another comment, I frequently will even out all the mine shafts in a single mine so that they each cost roughly the same amount for the next 1 level. And every time I have done that, Mine Shaft 11 has been far and away the best. I suppose it's a difference of how high up that is. So for me it might be Mine Shaft 11 at level 500 and Mine Shaft 20 at level 150, and both cost the same but Mine Shaft 11 gives more for a level up. But it might be the cast that later on in the game, if I have Mine Shaft 11 at 700 and Mine Shaft 20 at 350 or something, and both cost the same amount, Mine Shaft 20 would give more at that point.

But yeah, so far, I have never been at a point where Mine Shaft 11 wasn't the most cash-per-level per cash spent on upgrade. Hopefully that will change later in the game, I guess.

1
[deleted]•

[deleted]

1
[deleted]•

[deleted]

1
thefirewarde•

In my experience this only holds true in the early and mid game. How far in have you gotten?

1
d0llarbills•

I think people are getting hung up on the way you’ve explained the math. But suffice to say that shaft 11 is not universally the most efficient. But early on, it definitely feels that way. Different sections of islands, and different islands have different ratios. Also, it depends on your scaling. So if you always look at 1:1 levelling then 11 will always look great. Look at max:max and you’ll start to see a difference.

1
MagisterRo•

Correct. Shaft 11 is best for quite some time in early-mid and mid game but will become obsolete, as will most shafts, even 21.

My empirical rule is: level 400+ or 1. First level of a new shaft is always best as profit/Investment, but not always practical (e.g. after prestige, cash is no constraint but deeper shafts are unavailable yet; or you have more money than for 1 level, but next shaft is too expensive). Levels 2-299 are horrible. 300 may be OK esp. after a barrier jump (shafts 11 or 21).

400-440 or so is the sweet zone. When one can get next shaft to 400, do it! Sometimes old shafts make a brief comeback at 500 but not great compared to 2-3 shafts below at 400+. I've successfully used my 400+ or 1 rule between shafts 11 and 30.

Rationale: Decreasing returns to scale, both in levels within each shaft, and between shafts, with 'kinks' in the relationship at level 400 and shaft 21. As far as I found out from experiments, for all mines (except the event was different!)

Levels within each shaft. Not sure the formulas stay the same between shafts?

Up to L400: next level costs % more, profits % more.

Jumps of x2 at 10,25,50,(82??),100,200,300,400,500,600,700,800.

After L400: next level costs % more, profits % more. (Both way steeper than before L400).

Shafts 2-20: each next one costs ~17.3x more, profits 10x more.

Shafts 21-30: each next one costs 1000x, profits ~735x.

exceptions: big jumps at 6,11,16,21,26

This debate will become pointless, as later the Warehouse (transport+sale) is the most expensive subsystem and I know no way around it (like clever shaft leveling can do in early-mid-game; later those get negligible, 1-3% of investment). This already happened in the event and starts to happen in main game too, around ar-as cash.

1
ReflexManOP•

Alright, you are saying Mine Shaft 11 is most economical until roughly 500 or so, and at that point, the highest Mine Shaft I have access to will likely take over being the best investment beyond level 1?

1
MagisterRo•

The deepest accessible shaft is best IF just started, at level 1. More money into it is bad, until it can reach 300 or the sweet 400. e.g. L18 just got 400 and is great, L21 is at 1. Pour next money into L18 until L19 can get to 400. L19 at 300 is worse, L20 at 200 even worse.

1
ReflexManOP•

Hmm interesting. I wouldn't expect Mine Shaft 12 at 400 to be better than Mine Shaft 11 at whatever the equivalent cost is, based on what I have seen so far. But maybe I need to deliberately test that. Get Mine Shaft 12 to 400 and then level Mine Shaft 11 to the level where the cost for the next level is the same as the cost for the next level of Mine Shaft 12, and see which is better. Interested to see the results.

2
MagisterRo•

Now back with fresh raw DATA! From Platinum mine Prestige 2, multiplier 221.2x

You were right, shaft 11 is even more hugely good than I remembered. Shafts 12 and 13 scale badly, so 12/400 is worse than 11/417. 11/500 is still competitive until 15/439. From shaft 14 up, my 400+ principle holds. I estimate shaft 18 or so at 400+ makes 11 obsolete for good.

Sh12 L400 production 33ag Investment(1lvl) 87.3 ag

Sh11 L417 prod 35ag inv1 55 ag. >>> Yay for L11!

Sh11 L500 prod 7.22ai inv1 191ai >> Longer yay for L11!

Sh15 L439 prod 7.45ai inv1 1.35aj

Forgot to test 11/4xx vs 15/400, where 11 may not be so good as it doesn't get a new multiplier.

Sh15 L400 prod 33 ah inv1 1.13 ai >> So yay for 400+ at deeper shafts

Sh14 L417 prod 35 ah inv1 1.43 ai

Cost and profit increases between shafts, both at L400

10>11 cost 1750x profit 20,000x (YAY!!!)

11>12 cost 34.8x profit 10x

12>13 cost 43.3x profit 10x

13>14 cost 17.35x profit 10x

and the rest the same until 19>20, except

15>16 cost 10,000x profit 10,000x

1
TurbTastic•

It's all about the math. Whenever I'm deciding where I want to upgrade I do a quick calculation in my head. The two important things to consider when upgrading is the Cost of the upgrade and the increase to Total Extraction. Start with the Cost of the upgrade, and divide by the increase (the green amount) to Total Extraction. Let's say the Cost to upgrade is 500ac, and the increase to Total Extraction is 500ab per second, that means you'll earn back your 500ac investment in about 1000 seconds or 17 minutes (500ac/500ab=1000). Generally the amount of time it takes you get your money back keeps increasing as the level of the mine shaft increases. For some reason, mine shafts 11 and 16 tend to have cheaper Costs to upgrade than other shafts so that's why people like to focus on those. I usually don't hesitate on upgrading unless it takes over 2000 seconds to get my investment back.

1
ReflexManOP•

Right, and that's the same math I have been doing. I don't doubt that at a certain point (maybe a certain mine shaft beyond 23 starts being even more effective than 11, or maybe at a certain level of 11, it stops being as effective, etc), 11 starts getting trumped. But the point of my post was that, at every point I have been so far, the ratio of cost to upgrade and increase to total extraction have favored Mine Shaft 11. But other people have already given some good comments indicating when it is that 11 stops being the best. It sounds like even with Mine Shaft 23 available, 11 is still better until it gets beyond 500 or so, at which point some higher mine shaft can get to 400 and be the best one.

1
MagisterRo•

I do the same calculation.

MarginalPaybackTime = Investment / ProductionIncrease

but not always one level at a time! When the question arrives when to get the next shaft to 400, I get it to 350 (quite cheap by then) and look at the Buy 50 stats to include the bonus at 400. Then compare this whole chunk (350 to 400) with 1 level of the current main earner, say 437 to 438.

After getting the 2x bonus for the round hundred, the next levels are 2x better too (400 to 401 is almost 2x better than 398 to 399, would be 2x if not for the decreasing returns which are the general norm in these kinds of games)

1
ReflexManOP•

Yeah, good point. I hadn't considered comparing 1 level of a shaft to something-other-than-1 level of a different shaft, but the logic should work the same. I can still compare the ratios of each to determine that a new best shaft is around. Thanks!

1
MagisterRo•

The point is each of level 351... 399 alone can be worse than the current main shaft, but the chunk 350-400 is better because it includes the x2 jump.

Well, maybe not exactly 350 is the not-worth-it-point, sometimes it's 382 or so. The last levels before the jump are bad because of that universal decreasing returns to scale. But no point to reject them individually when they are the path to the jump. Then compare the whole chunk. Maybe a Buy10 for 390-400.

When I'll get a new prestige - rare these times for me - I'll test more precisely.

1
anguishedmoon71•

I’m seeing the same thing you are with shaft 11 but I’m really early in the game still. I have ruby mine and my coal mine is farthest along at level 20 so it may not hold true as I get farther along. I don’t know if my method has a flaw I’m not seeing but I set level upgrade to max and then I compare the amount in green under total extraction for each shaft picking the largest growth in total extraction. For me this is always lvl 11

1
MagisterRo•

Max level display is not bad early, when you DO have cash for several levels for the 'grain' not to be too big. It also doesn't include any jump that you're short of cash for, right now.

Later on you'll still rely on approximate mental divisions ;-) since 1 level of your best Investment will take hour(s) and you want to know which one before buying, not after...

I remember 11 is the best until 16 (or was it 18?) can get to 400. And definitely 1 of whatever is newest - but its push won't last long. [before affording it, and after you have cash for 2-9 levels, those DON'T pay well. Put cash into the latest 40x instead]

Now my main earners are shafts 27 at 400-415 or so. Also not too bad now, 28/30x and 29/20x. Inefficient now but possibly later, 30/10x.

1