Nishikori in his prime (whatever year you think that is; for me its 2014 or 2016) is going to play a best of 3 setter on hard court against the top 10 right now. How many does he beat?
-
Fritz
-
Hurkacz
-
Rune
-
Zverev
-
Tsitsipas
-
Rublev
-
Sinner
-
Medvedev
-
Alcaraz
-
Djokovic
I think he gets to djokovic, depending on what form sinner, meddy, alcaraz he gets. prime nishikori could even beat current djokovic, he did so against prime Novak in 2014 and other times. but current djok is more similar to fed, who usually had no troubles against him cause he could get out of trouble with his serve, and has a bit more variation now
The other time Nishikori beat Novak was in 2011 Basel, their h2h is 18-2.