I think it would depend on the stats used. Yamanote is still JR. The Joban line goes all the way to Sendai, if you really want it to. So if you got lateness st

I think it would depend on the stats used. Yamanote is still JR. The Joban line goes all the way to Sendai, if you really want it to. So if you got lateness stats on trains, it would likely take all the JR stuff and mix stuff up I agree with your sentiment, my comment is more about my theory that stats would not make the distinction (though it would likely exclude things like Tokyo Metro or the monorails).