Ryan Mason tries really hard. If Opta measured lungs bursted per 90, Mason would undoubtedly top the Premier League. And it's this very quality that has so endeared him to the Spurs faithful and led to calls for an England cap. People love the fact that he never stops trying.

As a midfielder in Mauricio Pochettino's Tottenham side, Ryan Mason has two jobs: press aggressively to win the ball and transition defense to attack with quick vertical passing. At face value, Mason seems perfectly tailored for this role. He's phenomenally aggressive and loves an ambitious ball forward. But it's these very strengths that have exposed his weaknesses this season.

Mason's aggression, while commendable, is often haphazard and directionless. The counter-press employed by Pochettino demands structured pressure on the ball, not aimlessly chasing it around the pitch. One statistic Spurs fans seem to love throwing around these days is the distance covered by a player in a match. Ryan Mason, unsurprisingly, covers more ground than most Spurs players every single game. Most fans seem to treat a high number of kilometers miles covered as an unquestioned positive. It's a number that represents effort and passion and hard work. But it's also a number that carries a downside in Pochettino's counter-pressing system.

To back up, the way a counter-pressing system works is for the team to apply pressure on the ball as soon as the other team gets possession. The theory behind the strategy is that counter attacks are the best time to score goals because the other team is out of shape while transitioning from attack to defense. If you can attack them while they're out of their defensive shape, they are more vulnerable. The goal of counter-pressing is twofold. First, it is intended to stop the other team's counter before it can create a good goalscoring chance. The second is to create a counter-attacking chance of your own.

The problem this tactic can run into is what happens when the counter-press breaks down, and Spurs have been incredibly susceptible to this problem all season long. As our own Michael Caley pointed out in a piece last month:

The problem for Spurs is what happens when the press doesn't work. The gegenpressing statistic measures how often Spurs break up opposition possession. With a rate of about 50 percent, Spurs are the second most successful club in the EPL at counter-pressing. But what happens the other 50 percent of the time, when the press doesn't work and Spurs' opponents retain possession? Chances and goals are what happen. When the opposition can break through Spurs' first pressing line, they find the field open in front of them and appealing lanes for either passing or running. Tottenham have conceded 10 goals following from new opposition midfield possessions, most in the EPL.

So while it may sound nice that the central midfielder is covering a ton of ground, the downside is that doing so means he is probably being dragged well out of position. When you have a guy who presses aggressively by running all over the pitch, instead of having the discipline to only press in a deliberate and structured manner, our team is even more out of shape than normal and therefore even more vulnerable to a counter attack. This very problem was remarked upon just the other day during the 3-2 loss to Liverpool, but it's been a problem all season.

Mason seems to have all the desire in the world to put himself about the midfield and help break up play, but what he lacks right now is the positional discipline to put himself about in the precise way the role demands. Looking at the above graphic, it's hard to even tell which end is ours. He's all over the pitch, but every one of those red dots represents a moment where he lost out to the other team, and left the defense exposed.

This lack of positional discipline has manifested in other ways as well. Against Arsenal, for example, for all his high energy running throughout the game, Mason failed to make the most important run of the game. Namely, the run to track Giroud into the penalty box on the chance Arsenal scored from. Covering a lot of ground is all well and good, but if you're not covering the right ground it doesn't matter.

Many Mason advocates seem fine with this trade off. The positives brought by his aggression and effort outweigh any increased defensive vulnerability. After all, we're winning a lot of games. But this results-oriented outlook crucially overlooks the actual chances we're creating and conceding. If you look at the number of goals we're expected to score and concede based on shot types and locations, we're outperforming the numbers by 10 goals. (For readers unfamiliar with what expected goals means, see here). In fact, the only teams whose expected goals against are worse than Spurs' are QPR, Leicester, and Burnley. We nip in just ahead of the abysmal Hull CIty.

So while the individual brilliance of Eriksen, Kane, and Lloris has pushed Spurs to heights perhaps undeserving of our actual performances at times, we can't count on them flying this close to the sun all season long without something crashing and burning. And if the magic wears off, the team needs to be set up in a way to cushion the fall.

At present, Mason's lack of discipline in midfield has caused a real problem, and it's a problem that has contributed to our defense being incredibly porous and conceding dangerous chances at a much higher rate than a team of our caliber should. Now, this problem isn't insurmountable, and indeed it's precisely the kind of problem you'd expect from a guy who as recently as last year was playing as a traditional number 10. It's his first season as a midfield pivot player, after all.

When people describe Mason now, the most frequent adjectives thrown around are words like tenacious, dedicated, passionate, energetic. What you don't often hear are words like technical, creative or goalscoring. This isn't a knock on Mason, but it is a massive shock given his history.

When Mason first started earning plaudits, it was decidedly not for his ankle-biting Wilson Palacios impersonation. While Mason seems to have sprung fully grown from the head of Mauricio Pochettino as a 23 year old midfielder, he actually first burst onto the scene back in 2008/2009. Instead of the midfield terrier you know and love today, back then he was busy scoring 29 goals in 31 appearances playing as a striker or second striker in the Academy League.* He was wonderfully creative, ran the attack, scored free kicks, and just generally ripped teams to pieces.

*This is according to Wikipedia, and has no attribution. According to a post from youth blogger Windy written at the end of that season, which frankly seems more reliable, Mason actually scored 37 and assisted 19. That's outrageous.

Mason's transition from youth team Maradona to midfield marauder is startling, and frankly a little miraculous. But despite his tremendous effort to make the position his own, the radical transformation of his game has left some unfortunate holes in his play.

Let's flip to the other task Mason is charged with when playing in Poche's pivot: quick, forward passing. While structured midfield pressure and positional intelligence may be something he needs to learn, surely he already knows how to pass the ball? As it turns out, yes and no.

There's no other central midfielder on a top seven side who completes as few of his passes per game as Ryan Mason

Besides his work rate, Mason's most valuable attribute as a Pochettino midfielder is his eagerness to attempt progressive, ambitious passes to transition quickly from defense to attack. They don't always come off, but he's definitely willing to try and make something happen. And in fact none of Nabil Bentaleb, Mousa Dembele, or Benji Stambouli attempt nearly as many forward passes or as many long passes as Mason does. The only one of Spurs' midfield options who can match Mason's ambition and range of passing is, perhaps surprisingly, Étienne Capoue. But since we may never see Capoue again, we'll leave him aside for the moment.

Because none of the other three midfielders (whose existence Pochettino acknowledges) have matched Mason's willingness to go forward and long with the ball, his place in the side is assured. But as with his relentless pressing energy, there's a downside to the passes he so willingly sprays forward. Because also unlike the rest of our midfielders, Mason gives the ball away an awful lot.*

*Capoue, interestingly enough, exceeds Mason in both number of forward passes per 90, and length of passes, while still managing the second highest pass completion percentage of our midfielders. Almost makes you wonder what could have been.

While the rest of our midfield quartet exceed an average of 85% completed passes, Mason trails behind at 81%. It's hard to put this number in meaningful context, because pass completion doesn't really mean anything on its own. The style of the team and the player's role in the side, among plenty of other factors, means that there's no uniform answer to what a "good" pass completion rate is.

That said, there's no other central midfielder on a top seven side who completes as few of his passes per game as Ryan Mason. His closest neighbors on the passing charts are instead the likes of Jonjo Shelvey, Joe Ledley, Danny Drinkwater, Tom Huddlestone...you get the idea. It's not great company.* None of Pochettino's midfielders at Southampton came close to completely so few passes last year either, so Mason's low percentage is not necessarily a deliberate function of team style.

*The only top seven midfielder who's close to Mason is Jordan Henderson, at 82%. But he creates twice as many chances per 90 as Mason, and what he lacks in accuracy more than makes up for in creativity. Again, context for this number is really hard. But no other midfielder on a good team is even close.

At this point I'll just ask you to accept that only completing 81% of his passes means he gives the ball away too much. (It just feels like he does, doesn't it?) I know that's a tough argument to swallow if you're not already inclined to believe it, but go with me for a minute.

So while Mason's completion numbers don't look like good central midfielder numbers, they do look a lot like attacking midfielder pass completion numbers. Because attacking midfielders (and apparently Jordan Henderson) are much more inclined to make risky, incisive passes to break down an opposition defense. The trade off between playing safe passes to retain possession and those riskier passes is that the risky passes are the ones that create scoring chances. And when they don't come off, they're far enough away from our own goal that they don't usually lead to dangerous chances for the other team.

Mason still seems to be passing like he's an attacking midfielder, but because he's further from the final third, these creative passes don't lead to nearly as many scoring opportunities, and when they don't connect with a teammate they leave the defense vulnerable.

As I mentioned above, when we turn over the ball we break up their counter attack right away 50% of the time. But the other 50% of the time? Really good scoring chances emerge for the other team. We've conceded a third of our total goals this season from these types of scenarios. So when Mason gives the ball away, and then charges out of position to press, and the other team gets past our pressure? We're basically in a whole lot of trouble.

Funny half from Mason. I'd never have thought five/six years ago that I'd be praising his tenacity/aggression but lamenting his passing. — Chris Miller (@WindyCOYS) February 7, 2015

So here again we have Mason struggling to adapt from the attacking midfield role he's played his entire career to the double pivot role he's asked to play in now. And again, we expect these struggles. It's hard changing the way you've played your entire career. Especially when taking on such a unique tactical gameplan as the counter-pressing system used by Pochettino. But while it's understandable, it's still incredibly damaging.

At his core Mason tries really hard. He tries really hard to motor around the pitch and harry opposition players. He tries really hard to play positive forward passes. But he seems to be trying so hard that he's failing to do his job. The only question that remains is, how hard will he try to fix it?

On that score, we can finally leave aside the negatives. Academy head John McDermott, speaking way back in 2009 about Ryan Mason's chances to make it in the first team said:

So what has Mason got that the others haven’t? Mono vision, says McDermott, who believes talent alone will take you to the age of 16, no further. ‘He’s incredibly dedicated, verging on obsessed.’ When Mason’s not playing football, he’s thinking about it or watching it and spent last night analysing the Arsenal game on Sky.

Assuming Mason hasn't lost that dedication, and if you've seen him on the pitch you can safely assume he hasn't, he seems well-placed to address his deficiencies. If he can attain the positional discipline required at this level, Mason could have a bright future with Spurs. But if he can't, then the very lung-bursting dedication that so endears him to Spurs fans will be the very thing that keeps him from being a star.