Spot the error

I think "It is difficult to say who is the better between the 2 players" sounds better.

I had read somewhere that which should be used for comparison

It is difficult to say who is the better player.

is "of" superfluous here?

av abhishiekis "of" superfluous here? No.

The word 'better' is used in relation to two things or people. So when 'better' is used, it is obvious that two things or people are involved.

Hence, 'better of the two players' should be reworded 'better player'.

Oh if suppose more than 3 people should I reframe the sentence as
who is the better among x,y &z

for 3 people , you should say : who is the best?

up I think "It is difficult to say who is the better between the 2 players" sounds better.

No, up — it doesn't.

Rover

Oh, yes. Thank you.