Then they are wrong.
May I kindly remind, we have no evidence that ranks even carry meaning. There is little to suggest the game assigns skill labels and ranks with fidelity and integrity. More than 1:1 players:accounts immediately cancels standard ELO/Glinko/TrueSkill ladder validity, and this team has written intent and motives (via patented rigging ™) to manipulate players.
Suppose ranks did mean something, then ‘diamond’ would be even more correct. Mainly for the sake of normal pdf inflection point. Around Diamond, you have the most sensitive dSR/d%people, and can infer more surprisal (a stats term) per data point. You can do this at mid-silver as well, but Diamond is better sweetspot, since it gives people something to aspire to.
From there, you discount (maybe sub-exponential kernel) a window above/beyond that locus.
See above. ‘mid-diamond’ (whatever that means) is ‘math better’ if you’re going for rank-based data. But there are better, less subjective methods, such as APM and accuracy % by sequence complexity (game tree parsing difficulty, principal variation ratios, traversal rates) to discern risk/reward values for various interactions (combinatorially up from 1v1 all the way to 5v5).
These are just some of the quantitative tools/techniques we use to mine strategies and ‘balance’ difficulty when trying to code general game playing bots/AI in say, military applications.
Of course, this isn’t used in the games industry because games are for fun and profit, not for winning wars against adversaries.
On a side note, if you wanted to balance (in a math sense, ignoring fun) for the ‘highest ranks’, you wouldn’t even use pro humans as playtesters. You would be using the top AI against top AI. And the results would be quite difficult to understand and probably look like turtleish boring play that cheese a pawn mismatch at depth 72. Or the OW equivalent of some ult economy delta during overtime.
They have consistently hired some of the worst decision makers in the industry.