Can I ask a question of interest?
Most "great" players of online Dominion set a bar on the Leaderboard above which you must sit to be allowed to play them. I get it, and it doesn't bother me personally. I understand that this bar is set to protect their ranking -- a loss to a low ranked player would disproportionately affect it.
Does this philosophy affect the "validity" of the rankings? I don't know how it works in other competitively ranked sports and games, so that's why I'm asking. For example, I think tennis rankings are based on participation and results, not on opponent strength.
I get the conventional wisdom that someone ranked 6000 should very rarely lose to someone ranked 2000. But is ensuring that 6000 doesn't play 2000 the best way to go about things? Is playing within your strata in any way artificially maintaining a ranking because it's impossible to lose many points?
(Yes, ranking limits are also used to ensure you play someone "worth" playing. Aside from that, I think it is fair to say that ranking limits are used to protect one's ranking as well.)