Countless factors influence a professional footballer's playing style; some physical, some psychological, some natural, some learned. Among the more obscure but most intriguing, though, is a player's experience of other sports.
Take, for example, Zlatan Ibrahimovic; it's unquestionably significant that a player renowned for scoring acrobatic goals with overhead kicks, scissor kicks and bicycle kicks has a black belt in taekwondo.
It's similarly notable that four of the five Americans, who have made the most Premier League appearances -- Brad Friedel, Tim Howard, Kasey Keller and Brad Guzan -- are goalkeepers, which makes sense considering their country traditionally excels in team sports where you use hands rather than feet.
Mousa Dembele, meanwhile, achieves hugely impressive statistics in terms of both dribbling and passing, but has managed just seven goals in five Premier League campaigns with Tottenham and sometimes appears completely incapable of shooting.
Why? Well, according to Dembele in a 2012 interview, as a teenager he "always played on the street with two lamp posts that were like a basketball pitch and we could not shoot. You had to dribble and touch the ball on the posts to score; we never shot the ball." Suddenly, the reasons for his limitations become clear He grew up playing a game that didn't involve shooting.
Another player who excelled at other sports was Alex Oxlade-Chamberlain. While his dad Mark Chamberlain played football for England in the 1980s, Oxlade-Chamberlain wasn't engrossed in that sport alone and was more of an all-rounder. His mum had a trial for England's volleyball team, so he comes from fine sporting stock.
Oxlade-Chamberlain was privately educated, which is rare among current English professional players, and attended St John's College, near Portsmouth on a sports scholarship. However, football was only offered until the age of 11, after which the focus was cricket and rugby.
He was already part of Southampton's academy but Oxlade-Chamberlain was also a fine wicketkeeper-batsman at cricket and excelled at rugby. He turned down trials for both Hampshire and London Irish respectively, to concentrate on his football career, although he remains handy at cricket and rugby.
Oxlade-Chamberlain is a naturally gifted sportsman first and foremost, rather than a pure technical footballer, who also has athletic ability. Football and cricket are so different that one is unlikely to impact the other in a technical sense, although both Gary and Phil Neville were excellent young cricketers and have spoken about that sport's impact upon their mental development.
The similarities between football and rugby are more obvious; that latter, after all, originated from the former. Both involve playing the ball between team members and, broadly speaking, attacking the opposition posts. The manner in which the ball is moved differs significantly, however, and that is where Oxlade-Chamberlain's footballing style becomes interesting.
The offside rule in rugby essentially bans forward passes and, therefore, attacking involves carrying the ball forward. Play a six-a-side game with a rugby-playing friend and their style is often very specific: Upon receiving a pass, they instantly charge forward, rather than stopping to assess passing options.
They naturally attempt to gain yards, before either storming past opponents with pace, power and a change of direction, rather than trickery with the ball. They offload the ball as a last resort, generally sideways, when their personal path to goal is blocked.
This, essentially, is how Oxlade-Chamberlain plays football. He's a ball carrier, who storms into spaces after receiving possession. In a positional sense, meanwhile, whether fielded on the right, left or through the middle, he essentially plays the same way, as a box-to-box midfielder-cum-winger.
And while his crossing has improved, he doesn't offer genuinely top-class end product; he's not fundamentally gifted at the basic art of kicking the ball. His scoring record is disappointing -- in six full seasons with Arsenal his highest total in all competitions is six goals -- as he often snatches at chances.
But more relevant, for a player generally considered an attacking midfielder, is that Oxlade-Chamberlain rarely plays penetrative passes. It's difficult to remember him providing anything that could be considered a moment of "genius," or any through balls behind the defence for onrushing teammates, and the stats show that he has assisted just 14 goals in 135 Premier League games.
That smacks of a "rugby approach" to the game; Oxlade-Chamberlain is a linear footballer, who carries the ball forward and passes it sideways. And this is essentially no different from his rugby-playing style: In a 2012 interview with Arsenal Magazine, he explained that, with the oval ball, he was "just the person that got the ball, ran quickly and tried to stay out of the way of any contact."
An 11-man team can only accommodate a certain number of creative players and, while many might have been waiting for Oxlade-Chamberlain to become a genuine attacking threat, he's always offered different qualities, like speed, energy, adaptability and commitment, which happen to be typical rugby attributes.
The widespread shift toward three-man defences encouraged Arsene Wenger to deploy Oxlade-Chamberlain as a wing-back in recent months, which seemed the best possible use of him; there's no other position where a player's role is all about getting up and down the pitch repeatedly, with and without the ball.
Oxlade-Chamberlain, however, appears to have turned down the opportunity to join Chelsea precisely because he didn't want to play wing-back in Antonio Conte's 3-4-3. His move to Liverpool is supposedly about a desire to be fielded in a box-to-box central midfield role, which seems peculiar considering how many other options Liverpool have in that position. Georginio Wijnaldum and Emre Can are more accomplished footballers, to the extent that club vice-captain James Milner hasn't been able to force his way into the side in recent weeks.
Indeed, it's worth remembering that Milner joined Liverpool for a very similar reason; he was tired of playing on either flank with Manchester City and was promised a central role by Brendan Rodgers. Last season, however, he found himself playing left-back, and now finds himself out of the team entirely. He is, to a top side, no more than a handy, workmanlike utility man, and it's difficult to see how Oxlade-Chamberlain differs.
He might well be suited to Jurgen Klopp's overall system, however; an approach that is based around physicality, energy and sprinting forward whenever possible. That is, after all, Oxlade-Chamberlain's natural rugby-style game. But there are few signs he possesses the required intelligence to play in the central midfield, and with Adam Lallana still to come back into contention for Klopp's side to provide that creativity, and the brilliant Naby Keita set to arrive next summer and provide true all-round qualities, one can't help feeling that Oxlade-Chamberlain will have to settle for a fringe role.
Nevertheless, while Oxlade-Chamberlain admits he's gone off rugby in recent years, his experience of the sport remains obvious in his playing style. He is essentially a runner, a worker, a ball-carrier. Playing in a pressing-based Liverpool makes some degree of sense, but it's difficult to shake the feeling that a role as a wing-back for reigning champions Chelsea would have suited his skill set much better.