The FA permitted artificial turf (3G) pitches in all rounds of the competition from the 2014–15 edition and beyond. Under the 2015-16 rules, the pitch must be of FIFA One Star quality, or Two Star for ties if they involve one of the <answer>92</answer> professional clubs. This followed approval two years previously for their use in the qualifying rounds only - if a team with a 3G pitch progressed to the competition proper, they had to switch their tie to the ground of another eligible entrant with a natural grass pitch. Having been strong proponents of the surface, the first match in the proper rounds to be played on a 3G surface was a televised first round replay at Maidstone United's Gallagher Stadium on 20 November 2015.
How many professional clubs are there? 
92