Try as I might, I can’t quite pin down Arnold Allen . I know where he is, to be clear: as we speak via video call, Allen in a rented residence in Las Vegas, a day after completing the journey from his home in Suffolk. But in trying to get to the heart of who the UFC ’s No 7 featherweight is, I find him reliably elusive. I suppose I might be missing the point. Allen, one of British MMA’s top talents, is generally shy, rarely loquacious. So when these attributes come across in conversation, maybe I am scraping his core. Perhaps I’m greedy in wanting more; perhaps the journalist in me has a misguided sense of success and failure in the endeavour of getting to know a subject. You want them to open up, so when Allen begins to shut down towards the end of our chat, I feel like I’m bothering him – and on the eve of a dangerous main event against Melquizael Costa, no less .…