Classic example of Deus ex machina for Ishikawa. Definition from Wikipedia: "
Deus ex machina is a plot device whereby a seemingly unsolvable problem in a story is suddenly and abruptly resolved by an unexpected and seemingly unlikely occurrence, typically so much as to seem contrived."
The way everyone has been reacting makes it seem that Ito losing her singles spot is a foregone conclusion. However, in my opinion, Ito is still leading the race if you consider that she's played only 6 events as compared to Ishikawa's 7 events and Hirano's 8 events. Ito's advantage is her WTTC 2018 result, which merited her 2000 points, which is the most a Japanese player will probably get from a single event (unless someone unexpectedly wins a WT Platinum event). In a ranking system that only counts the Top 8 results, getting more ranking points from a single event is more advantageous since the lower results can be replaced. To illustrate, let's say player A played 2 tournaments and got 2000 and 500 points for a total of 2500 points. Player B got 1250 and 1250 points from the same 2 tournaments also for a total of 2500 points. Player A has the higher upside to gain more ranking points. Why? In the next tournament, let's say both players got 1500 points. Player A lowest result of 500 points will be replaced while Player B's lowest result of 1250 will be replaced by the same 1500 points. Player A will end up with more total points all thanks to her single event giving her massive points in one sitting.
Certainly, Ito has less breathing room now, but as long as she doesn't crumble horribly, she should be fine. I used my excel sheet to compute possible scenarios should Ishikawa and Hirano both finish as semi-finalists in the World Cup, but Ito would still lead them by a few hundred points as long as she can finish in the QF in at least two more World Tour events. This is contingent on Ishikawa and Hirano not progressing further than the QF in the World Tour events, which should be the case as long as China continues to control the top 4-5 positions in the WR and there's no "match-fixing."
In fact, I still believe Hirano is more in danger of losing her spot to Ishikawa than Ito is. Hirano is still the 9th seed and will face Chinese players or Ito/Ishikawa in the R16 of World Tour events at the latest. Furthermore, she's not going to be a Top 4 seed for the World Cup, which makes a SF finish more difficult for her. She has a 50% of meeting a Chinese player in the QF. She has a 25% chance of meeting Ishikawa. In this matchup, only the winner can get the lion's share of the WR points, while the loser gets less points due to a QF finish. Based on my computations, Ito will still have more WR points than whoever loses that match. Hirano has a 25% chance of meeting Cheng I-Ching and Hirano isn't that heavily favored over her since Cheng has beaten Top Japanese players in the past and has even beaten some lower-ranked Chinese players.
Assuming seeding in the first T2 Diamond event is based on WT standings, Ito is favored to make at least the QF since she won't face a Chinese player in the first round due to her seeding. Ishikawa and Hirano are in the bottom 8 of the WT standings for the T2 qualifiers so they need luckier draws to make it further in the tournament.
One thing to consider, however, is the World Team Cup. The player chosen to play the first singles match is expected to get at least 1200 points (4 wins for 4 rounds with 300 points for each win.) This is if Coach Baba doesn't rotate the player chosen to play 2 singles matches for the entire duration of the tournament. This would give the player chosen to play 2 singles matches an unfair advantage over her teammates since she would essentially play more matches than her teammates in the same tournament, which will lead her to more wins and more ranking points.
