A smile can camouflage a stubborn streak. Roberto Martinez can appear one of the most amiable, amenable men in the cut-throat business that is football management but he can be as obstinate as any of the more awkward characters to occupy a dugout. He just has a different way of showing it.
The new Everton manager allies industrial quantities of belief in his methods and ideas with a refusal to be concerned by conventional wisdom. In his days at Wigan, he was almost deliberately different and not because winning the FA Cup and being relegated in the space of four days proved a unique journey from high to low. Tactically, Martinez was happy to be the exception, acting as an evangelist for a back three over two seasons when every one of his counterparts in Premier League management employed four defenders.
Despite Wigan's eventual demotion, much of their success in that time - particularly their seven victories in the last nine games of the 2011-12 season and their FA Cup run last year - can be attributed to their formation. Or, perhaps more accurately, one of them: mid-match switches between a three- and four-man defence were frequent occurrences last season.
And so, while Martinez has begun his reign at Goodison Park by persevering with the 4-4-1-1 that was David Moyes' trademark system, it might be an idealist showing his pragmatic streak: if it ain't broke, don't fix it. "It's important that the team don't lose what they're good at," Martinez said when unveiled. "They are special at many aspects of their game, and what we need to do is carry on improving. It's important we get our players to be excited about the next stage at the football club."
Yet given his steadfast belief in his methods, it is easy to imagine the next stage, in his eyes, incorporates a back three. It is also pertinent that, despite Everton's effectiveness playing 4-4-1-1, which enabled them to combine solidity with steel, few squads in England are as equipped to be reconfigured.
Given wing-backs' significance in Martinez's favourite shape, it bodes well that Everton have perhaps the finest pair in England. Leighton Baines has been unrivalled at left-back for a couple of years and, as the leading chance creator in Europe's top five leagues last season, could be still more productive if he had fewer defensive duties. The similarly dynamic and much improved Seamus Coleman has started to mirror Baines' displays on the opposite flank.
Operating in a back three places different demands on central defenders; footballing ability is required, especially in a Martinez team, if they are not to have three passengers in possession, while speed is essential to cover when the wing-backs advance. Again, the Spaniard is well served. Sylvain Distin has a turn of speed that belies his 35 years and as one of the comparatively few left-footed centre-backs, is suited to a slightly wider role.
Phil Jagielka served much of his apprenticeship at Sheffield United at right-back and in midfield; the best English centre-back is more than simply a stopper. If Johnny Heitinga's form last season qualifies him to play neither in a back three nor a back four, the recent recruit Antolin Alcaraz was at his most authoritative for Wigan as the central figure among three centre-backs.
At the other end, Martinez has already recreated his attack at the DW Stadium by recruiting Arouna Kone. The Ivorian offers a counter-attacking outlet to complement the technicians behind: indeed, while Wigan's system was often deemed 3-4-3, the most accurate description is 3-4-2-1 with two tiers of twin technicians.
At the heart of the midfield, Darron Gibson and Leon Osman offer an Evertonian equivalent of James McCarthy and James McArthur, with a deep-lying distributor offering footballing intelligence. The emphasis is on distribution, rather than being a defensive midfielder.
Then comes the problem. To accommodate a third centre-back, someone has to be sacrificed. Realistically, that means either the support striker or one of the wide men. Specialist wingers can be rendered redundant by a wing-back formation but, as Everton's veered infield anyway, they actually bear considerable similarities to Wigan's flair players. Like Shaun Maloney, Steven Pienaar is a natural No. 10 who can also play on the left. Like Callum McManaman, Kevin Mirallas offers pace and dribbling skills. Both are post-modern wingers, playing between the lines.
Then there is the exception, lacking a Wigan counterpart. Marouane Fellaini is the odd one out, and not least because he can be a target man who enabled Everton to go from back to front quickly. Moyes' 4-4-1-1 revolved around the Belgian and Tim Cahill before him, abrasive players operating in an area often populated by aesthetes. Martinez has the option of dropping Fellaini into the heart of midfield but his continuing presence at Goodison Park perhaps explains why, so far, there has been no systemic change.
But if going from 4-4-1-1 to 3-4-2-1 now would mean benching one of Fellaini, Pienaar, Mirallas, Gibson and Osman, each a fine performer for Moyes last year, the switch could be simpler in the future. If a club in the Champions League activates the hirsute talisman's release clause and given the impossibility of finding a like-for-like replacement for an idiosyncratic player, Martinez's preferred shape may be Everton's post-Fellaini formation.