Teams were allowed up to three challenges in televised matches but no decisions were reversed all season so the experiment has been dropped.

Now only requests from on-field umpires will be referred to the third official.

International rules on powerplays and a change of ball after 34 overs have also been brought in for the FP Trophy.

And the number of overs per day in the County Championship will be 96, with three two-hour sessions on each day.