# Skills cost/benefit, mining and "under-mining of skills"

**URL:** <https://forums.eveonline.com/t/skills-cost-benefit-mining-and-under-mining-of-skills/502421>\
**Category:** Science & Industry\
**Created:** [December 5, 2025, 5:12pm UTC](https://forums.eveonline.com/t/skills-cost-benefit-mining-and-under-mining-of-skills/502421 "2025-12-05T17:12:56Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![Gerard\_Amatin](https://sea1.discourse-cdn.com/eveonline/user_avatar/forums.eveonline.com/gerard_amatin/32/481361_2.png) [@Gerard\_Amatin](https://forums.eveonline.com/u/Gerard_Amatin)\
**Post date:** [December 5, 2025, 8:56pm UTC](https://forums.eveonline.com/t/skills-cost-benefit-mining-and-under-mining-of-skills/502421/6 "2025-12-05T20:56:34Z")

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> [@Fidd](#):
>
> Earlier today I counted circa 43 consecutive mining cycles with no critical hit,

With the skill at level 5 you have increased the default crit chance by 50%, from 1% to 1.5%. Or from one in 100 to one in 67.

Without other sources of crit, the chance of not critting for 43 cycles in a row is ((100-1.5)/100)^43 = 0.52. Or in other words 52%.

Your observation is like flipping a coin and calling it strange that it fell on heads instead of tails.

It’s not a rare occurrence what happened to you.

> [@Fidd](#):
>
> The wording of “Mining Exploitation” and “Mining Precision” is a little ambiguous, as it could be per turret, or, an overall chance on a pair of lasers. Either way, assuming it starts at 1%, then it’s reasonable to interpret that the 25% increase in chance is likely to be a minimum 25% or 1 in 4 cycles at the most disadvantageous interpretation.

It is true that the mechanics behind critical hits in games aren’t always immediately clear on first sight.

This is why you likely are not the first player with these questions. Other players too have wondered “how do crits work” and some wrote down their findings. A quick google search could give the answer, or just a search on the forums too can also explain the details, like in this thread by me:

> [@Mining Critical Hits Explained](https://forums.eveonline.com/t/mining-critical-hits-explained/499670):
>
> The upcoming [Catalyst Expansion](https://www.eveonline.com/news/view/catalyst-expansion-launches-18-november) brings to us “Mining Critical Hits”. What are those? Well, the test server was up, so I took a look. (Also take a look at my other Catalyst thread about the [yield of the new mining ships](https://forums.eveonline.com/t/yield-comparison-of-the-new-mining-ships/499595)). Crit skills Currently all ore and ice mining equipment has a base 1% chance at obtaining 200% bonus crit yield. (Numbers subject to change). This can be improved with two skills, Mining Bonanza Exploitation for 5% crit yield per skill level and Mining Precision f…

> [@Fidd](#):
>
> Either way, assuming it starts at 1%, then it’s reasonable to interpret that the 25% increase in chance is likely to be a minimum 25% or 1 in 4 cycles at the most disadvantageous interpretation.

If it starts at 1%, assuming that a 25% increase goes from 1% to 25% is a pretty bold assumption. That would mean that a mere 25% increased crit chance boosts your yield by 75% (if crit yield is 200%), or that the crit chance bonus of the Venture Consortium Issue of 50% crit chance more than doubles your yield as Venture pilot.

For a game that’s all about a 5% increase here, a 10% there from modules and skills, your assumption is like an order of magnitude off. That might be a hint that the assumption is wrong.

> [@Fidd](#):
>
> Thus over 40 cycles one might reasonably expect around 10 crit hits.

A reasonable assumption based on your earlier assumption, but that first one was likely wrong.

> [@Fidd](#):
>
> This is not by any yardstick a fair or reasonable effect for the 2M or so skill-points expended.

You can stack crit bonuses of various sources, which gets massively boosted by those two skills. With good bonuses, links and skills you can increase your yield by up to 25% from crits. Or that was when I did the math initially before abyssal miner stats were released, with abyssal rolls it can be even more. And this extra yield isn’t taken from the rocks, so it also increases the amount of valuable ore you can mine by 25%.

I think it is very well worth the skill points used.

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