I'm sorry to point out the relative futility of the exercise as it is carried. First I'm not positive about the usefulness of the tier list as presented by the TS, but I wouldn't say I have anything against: it does present useful data (specs) to a lot of knives reunited in a list. I'm all for something like that, and taking into account that the tiers are but mostly reflecting subjectivity, it's alright. I also appreciate the effort truly: more on that below.
But here the specific interaction about the edge retention is cause for alarm, or at least, can be easily misguiding especially as it SEEMS to go against logic.
As answered by the TS and the further comparisons he gave, here we have one unit in W#2, one in W#1, and one in HAP40. I am fully aware that the TS is using a relative, circumstance-based appreciation of it: an approximate amount of time relying on similar use described as "home use, large variety of vegetables" as reiterated in the interaction, but also and just as important, relying on tomatoes as the "bench test" and describing use as "heavy handed". That is alright with me really: I think it does single out logical markers for a relative, circumstance-based appreciation of retention.
However it does get misguiding when considering the steels here vs. the relative, circumstance-based appreciation of retention.
Of note before I explain that, here we have three steels that, when HT'ed to their typical hardness (in order around 61, around 63, and around 66 RC) will have quite similar toughness each (little over 5 ft-lbs). Also of note, while the typical retention expected from W#2 to W#1 would be relatively similar (circa 300 TCC in Catra where you'd expect W#1 at its typical hardness to do a bit better than W#2 at its typical hardness, but in reality the difference would be quite marginal still), when it comes to HAP40 you would be expecting twice the edge retention of the White steels (and most Carbon steels as well, give or take some margin and of course not confounding "Carbon" steels as an often use generalization of many Low-Alloys as well).
But from the TS what we have initially is a comparison of W#1 with HAP40 where W#1 lasted 2 weeks and HAP40 lasted 3 weeks. And although it is already a bit off chart, it could still be explained, with everything else considered either typical (HT of steel) or similar (geometry sharpening etc.), by the possibility that HAP40 could in effective use perhaps be more prone to micro-chipping. However, we would have to relativize that with the fact that HAP40 would be much less affected by corrosion wear than White steels, and if we're talking a large variety of veggies and repeated cutting of tomatoes (the bench), we're talking about an undeniable amount of corrosion wear no matter how OCD one is with wiping the blade along the way. Still, I can accept such a reporting of edge retention because, indeed, we do not necessarily have everything either typical or similar here. And because it is a relative, circumstance-based assessment.
However, the TS there adds another comparison: the Kuwabara. That is, the W#2 steel, which is not only technically the weakest steel for edge retention of the three, but also well-known to be easily worn out through corrosion only. And the assessment is that it lasted 4 weeks +, and that it was the only one out of the three to present micro-chipping.
Now that throws entirely out just how I can appreciate the first comparison to just about make sense. Because first you'd never expect W#2 to win so entirely the retention game over HAP40. To accept that is to know that there are EXTREME differences in steel HT, geometry, and sharpening, and... well let's not compound stuff and just say "etc".
But even more so telling is that "4 weeks +" and micro-chipping for W#2: that makes you consider that not only W#2 endured 1.5 times as much as HAP40, but also that it went to chip, which begs the question: if not of that chipping, would it have lasted even longer that 4 weeks +???
But much more obvious is then another question: if the HAP40 unit DIDN'T micro-chip, then what the hell explains that it so mildly outlasted W#1 while being squashed entirely by a W#2 that effectively was possibly brought to its knees from micro-chipping in the end? Only possible way to explain that is, as I said, extreme divergence of either typical steel HT, geometry, thinness BTE, or then it would seem most likely, of user-induced extreme divergence. And the list of causes is just about endless, but let's say for example that I would easily believe the HAP40 unit not to have been sharpened optimally, or just quite simply that it is improbable to even "relatively similarly" reproduce the use of one knife against another for long expenses of time due to various reasons.
Now as I said I appreciate the effort of the TS and don't want to condemn it. In fact, I'd like that he would tighten his tier repartition on hard, undeniable facts of quality, while loosening his edge retention assessment to something more like "about as expected for steel", "it seemed better than average" or "poorer than average" and rather let the expected intrinsic scientifically verified qualities of the steel do the extrapolating maths of retention as it should scale in a time fashion or amount of stuff cut fashion relative assessment.
I respect that the TS has tried a lot of knives, and I think it works in his favor to pursue his goal with the tier list and the reviews. I respect that he makes a good job to relativize his own means. I just think I should encourage him to revise the rigor of his methods to a better use of his comparisons, to question himself when encountering largely digressing "relative data" before posting anything, and to avoid acknowledging another KKF user's belief of his analysis of only one unit of a knife to even bluntly affirm (probably not intended this way, I know, from his part) that White #2 was 1.5x as enduring as HAP40 without at the same time making a case of the statistical discrepancy and that he wouldn't take his own assessment to the bank. Also working would be to say that the assessment was only sampled "as experienced" from the one knife and his own sharpening and cutting skills/method, and should not be immediately correlated with such an assessment of another sample of another entirely different knife.
