Nothing captures pre-season fever quite like tweets demanding clubs to "Announce trialist B". Bristol Rovers have had their fair share of success with trialists, perhaps more than most clubs in recent times.
The greatest success of all was Billy Bodin, who would become a modern Gas legend with his incredible performances in the promotion-winning campaign of 2015/16. He arrived at Rovers with a questionable injury record but left a hero as he earned a deserved move to the Championship.
Bodin was an outlier. The reality is it very rarely works out like that. More often than not, trialists come and go without making much of an impression, and some don't see the pitch at all.