These are the critical effective stack depths at which your villain makes dramatic adjustments to their preflop ranges when facing a minraise.  A good, balanced player should not have these, but most do.  Before explaining why, I should define them.  There are two:
 
1) Skates Calling Point (SCP) - This is the effective stack depth at which your villain switches from an all-in or fold strategy to one that incorporates calling.  When facing a minraise at 2BB, your villain can only go all-in or fold.  At 5BB, nearly all villains will either go all-in or fold.  At 10BB, some will mix in calling with some hands.  The effective stack depth where the calling frequency becomes significant is the SCP.
 
2) Skates 3-Betting Point (S3BP) - This is the effective stack depth at which your villain switches their 3-bet sizing from always being all-in (or committing) to having a significant fraction of their 3-bets being non-committing.  At 15BB, if a villain 3-bets when facing a minraise, they will almost certainly go all-in with the majority of their range.  At 22BB, some villains will keep going all-in, but others might switch to smaller 3-bets.  The effective stack depth where the frequency of the non-committing 3-bet size becomes significant is the S3BP.
 
When I say "majority" and "significant", I am referring to a range that does not incorporate AA and KK.  Many players play in unbalanced ways with those two hands, and in this case, we would like to remove them from consideration.  Some people, when you minraise at 10BB, will flat or min-3-bet with AA or KK and only those hands.  This is not what we are looking to isolate.
 
When talking about SCPs and S3BPs, it might be helpful to refer to them as "hard" and "soft".  A "hard" SCP is what most players have.  If Mr. StandardVillain has been reading 2+2 for the past year, he might have learned that when facing a minraise at less than 20BB, he should either go all-in or fold.  At 20BB though, he should start to call with most hands because he does not want to risk more than 19BB to pick up 2BB.  This means that StandardVillain has a hard-SCP of 20.  This is a very common behavior among weaker players and mediocre regs at this point in time.  Historically, I think this is because the average hero often had a very wide open % (say, 80%), and a very tight call % (say, 12%).  Playing the way the StandardVillain played was incredibly profitable.  Now, the average hero at higher stakes might still open very wide, but has often adjusted to having a wider calling range, neglecting the primary source of equity won by StandardVillain.  As such, many of the stronger players today do not have SCPs at 20, but rather closer to 15.  If instead of having a hard-SCP, StandardVillain were to start gradually incorporating hands into a calling range at 18BB, he would have a soft-SCP at 18.  Very strong players have soft-SCPs that are very hard to define because they adopt mixed-strategies (they do not always play a given hand the same way).
 
S3BPs are almost always extremely hard (non-gradual), and are usually in the range of 22-25BB.  Sure, StandardVillain might always jam 33 if hero limps into him, but the rest of StandardVillain's 3-bet range is likely to have a 3-bet size between the range of 4BB to 6BB.  Most people have a fixed 3-bet size that they switch to when the first incorporate non-committing 3-bets.  I can not think of one villain I have come across who does not.  Of course, we ignore behavior with AA and KK.
 
Now that we've defined these... can you think of any forum members or coaches that have well-defined SCPs or S3BPs?  Are they hard or soft?  How many of them that have easily recognized hard-SCPs play high-stakes?  The answer is probably close to zero, and here's why:
 
If I can notch you into a box, I can read your frequencies and exploit you.
 
Over the course of a match or series of matches, a good hero attempts to best understand the frequencies with which their villain takes each possible action on each street, then utilizes that information to make estimations of villain's range on each street, then utilizes that information to come up with a maximally exploitive strategy to combat those ranges.  Although I would be happier putting a lot of caveats and footnotes in there, that is some very rudimentary poker theory.  As a consequence, anything that allows the hero to get a better estimation of those frequencies enables the hero to make more precise adjustments to better exploit their villain.
 
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Stop here, take a breather.  You should be able to extrapolate the rest of this article from what I've said already.  I will walk you through it, but I strongly encourage you to step back and not continue reading until you try to figure it out on your own.
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Hello again!
 
If you play within a well-constructed set of rules, or box, your easily observed frequencies no longer tell a part of the story; they tell the whole story.  If after one game with you, I observe what I think to be a hard-SCP at 20, I am immediately estimating a 3-bet frequency I think you have at each depth below that.  If I've played many games with you, I can just look at my database and pull the information directly.  Then, what do you think my adjustments look like?  Fix a stack depth and consider a range of villain 3-bet frequencies.  Take a moment to try to come up with my opening range with respect to those frequencies on your own.
 
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Anddddd here you go: If your frequency is lower than 50%, I will raise any two cards.  I'm not going to spell that one out for you.  If you don't see why that is the case, you need to step back and think about it more.  If your frequency is higher than 50%, I will raise any hand that I am also calling a jam with, and fold all hands I would fold to a jam with.
 
So what is the result?  I have a raise/fold range if and only if I think your 3-bet frequency is less than 50%.
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Now... here is where things really get interesting, despite the simplicity of the topic.  Notice that my adjustment is not continuous; I don't gradually add hands into my opening range.  Since you are playing within this box that you have defined for yourself, my adjustments are effectively in the binary.  I either raise everything, or I raise my calling range, and which strategy I adopt is dependent solely on your 3-bet frequency.  (Of course, the size of my raise-calling range will vary based on your 3-bet frequency and the effective stack depth).
 
If I think you 3-bet all-in with 50% of all hands at 15BB, then my raising frequency at 16BB is likely to be 100%, but my raising frequency at 14BB might be something like 40% (and raise-calling my J9s :)).  If someone were to isolate my hands from 14-16BB, they might see my raising range at something like 70%.  Do you see why their adjustments might be mistaken or flawed?  Do you see where I might be able to pick up an edge from this?  Do you see how difficult it is for someone with a hard-SCP to compete with me?
 
So what about S3BPs?  These are much more interesting because this part of the game is not wel-evolved.  At this time, most strong high-stakes HUSNG players have soft-SCPs that are extremely hard to discover.  On the other hand, hard-S3BPs are still found in virtually everyone; I'm currently thinking of only a few exceptions.  When thinking about a hard-S3BP and the adjustments you can make relating to it, consider how a villain views your calling frequency and 4-bet frequency when facing a non-committing 3-bet.  When they 3-bet non-committing, are they polarized?  Are they merged?  What does their 3-bet frequency look like below the S3BP (when they are only going all-in).  Does it increase or decrease on the other side of the S3BP?  What does that say about their calling range around the S3BP?  What does that mean your opening range should look like?  What kind of tricks can you pull?  I'm not going to spoon-feed this one to you... figure it out :).

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-Skates / psimalive