Because of
the way Ratingscentral work, especially the assumptions on matchup which is a major factor in pro table tennis, and also the fact that CNT players break the curve, making direct comparisons between players are inherently difficult, where
the mean and the SD have to be considered together. So instead of the point difference, I'm more concerned with their relative positions because a ranking system is supposed to properly reflect the clues drawn from what a rating system is designed to do - predict the outcome of a match based on past results.
LYJ
has never beaten Harimoto in their 3 formal encounters(disregarding the T League, where Harimoto was losing left and right, and Ratingscentral doesn't take that into account either). Putting LYJ above Harimoto suggests
those 3 losses were upsets, which is counter-intuitive for a system based on belief(probability). OTOH, under the ITTF system, LYJ was only 50 points behind in February and would've knocked Harimoto off the 5th spot had he closed out the match against Mizutani at the German Open. Hence, the ITTF system also suggests they're close in
strength, given their
performance in the past 12 months.
Same deal for Ishikawa, CIC and FTW. Ishikawa has always had trouble playing these two. She still has a winning record against them, but her recent encounters were losses, so the ITTF's merit-based system better reflects their recent performance. In CIC's case, her most recent 2 wins came after she started working with Zheng Jiaqi, which also helped her against Ito, despite losing 3 out of the last 4. In FTW's case, she also beat CM last year just like Ishikawa did.