The soccer coach whom the players respect

[waverider]

In this original sentence, I think 2 commas are not necessary in order to identify "which" coach. Is this thinking correct (restrictive clause)?

(a) The tennis coach whom the players respect was a national champion five years ago.

(b) The tennis coach, whom the players respect, was a national champion five years ago.

 

[jutfrank]

In sentence a), the relative clause identifies which coach.

In sentence b) the relative clause does not identify the coach—it gives extra information about the coach.