On the few occasions I have seen Mason Crane bowl the one thing I have noticed is that he certainly doesn't seem to lack confidence in his own ability.On the "Rashid" thread (which I must confess I re-read this morning as I don't quite know what to think about it all now), I responded to a question about Mason Crane and why he would most likely be on the plane to Australia. My answer was that he is regarded as "the next big thing" and that this pursuit of the youthful mystery spinner has been the dominant England approach since at least the days of Richard Dawson and Chris Schofield (and more recently in the days of Simon Kerrigan and Danny Briggs), but it hasn't been noticeably successful.
The old orthodoxy is quite well expressed by Alec Bedser (or his ghostwriter), who in 1952 wrote: "Because of this necessity for more accuracy, which can only come from long practice and experience, it will be found that slow bowlers, especially in English cricket, usually come to prominence later in life. J. C. White, T. W Goddard, C. Parker and Hedley Verity, to name just a few of the really great slow bowlers, did not gain real recognition until they were approaching thirty years of age." (Bowling, p. 42).
The best of the recent England spinners, Swann, wasn't really a regular member of the team until the age of around 28-29, though he had been involved in the England set-up at a much younger age. It seems that if you aren't somewhere in the mix at an early stage, it's very difficult to break through in later life. Hence Gareth Batty seems to get the occasional "recall" every five years or so, whereas a player like Gary Keedy, who I always thought was a more menacing bowler, never got a look-in. Where there have occasionally been exceptions to this "rule" - e.g. Shaun Udal - I don't think the results were bad, but the rule seems to have remained in place.
Selection's a highly selective matter, but where the whole set-up is geared to a particular pattern - especially when it's a pattern that isn't based on historical evidence - the chances are it will grind down and demoralize talented people who might have quite a lot to contribute. It seems, for example, that Jack Leach at 26 no longer interests the selectors, whereas there's apparently some excitement about his younger colleague Dom Bess who has just turned 20. I hope I'm wrong, but my suspicion is that the "next big thing" pattern seems set to perpetuate itself without bringing any great success.
Confidence of course can be misplaced, but I think it's essential for a spin bowler in Test match cricket who is expected to bowl quite a number of overs in both innings, even when conditions may not be spin friendly.
Swann had it, Moeen certainly doesn't and Rashid seems to have found it, but only in white ball cricket.