German soccer has been the engine of innovation to the sport in recent years. Hyper-pressing managers Jürgen Klopp, Roger Schmidt, and Pep Guardiola all developed their own form of a fast, physical game based on creating and then exploiting transition opportunities. It's an exciting style, so much so that it can seem to prioritize excitement over effectiveness even while winning league titles for Bayern Munich and Borussia Dortmund.

This year, RB Leipzig and manager Ralph Hasenhüttl have taken the league by storm with a compelling twist on this style. They ask the question: what if Bundesliga soccer were more orderly, less chaotic?

Last season, RB Leipzig was promoted from the 2. Bundesliga in second place. They were expected to stay up without challenging for European places, but instead, they've surged all the way up to second place, and they've done it by focusing on defending.

It is not that Leipzig doesn't press or break at speed. It's not that Naby Keita is anything less than one of the most fun players to watch in Europe. But the reason RBL has been so effective this season starts at the back with a defensive philosophy that trades in the traditional, pragmatic virtues. You know, the boring ones.

RB Leipzig really is this good

We have to establish that RB Leipzig is not a fluke. The East German upstarts deserve their position, by all measures. While Leipzig's potentially buoyant Cinderella story — from the lower divisions to the top of the table! — is weighted down by the deep, corporate pockets of the club's ownership, the quality of the team is undeniable. RB Leipzig is not only in the thick of the title race but they have a statistical profile worthy of that position.

By expected goals, a measure of the quality of chances created and conceded, RB Leipzig has been the best team in the Bundesliga so far. In fact, over the last seven seasons only Bayern or Dortmund has bettered their plus-14 expected goals difference through 14 matches.

It is fair to say that given their transfer and wage spending, Leipzig should not be compared to other recently promoted sides like Darmstadt and Freiburg. However, if you compare Leipzig to large, wealthy clubs like Wolfsburg and Leverkusen, it still comes out clearly ahead. From dozens of opportunities in the same time period, those clubs only made this chart once (Leverkusen in 14-15), and Leipzig is here in its first season. RBL is not only a true title contender, the side is also significantly outperforming the baseline for a moneyed and powerful Bundesliga side.

One bit of good fortune has fallen Leipzig's way. While Dortmund and Bayern still have good teams, neither appears likely to run away with the league as they so often have. Leipzig, like Leicester City in the Premier League before them, may be peaking at exactly the right time, in a league without a dominant power to hold off its challenge.

The secret to their success is defense

The most impressive of Leipzig's statistics are not on the attacking side. No one in the Bundesliga has a defense to match RBL's. Hasenhüttl's club has conceded by far the fewest clear scoring chances and the fewest chances from direct attacks (attacks where 60 percent or more of the action is directly toward goal). Other teams cannot break at speed against Leipzig and they can't get in behind the side's midfield and defensive lines.

Leipzig's defensive style is in general far from innovative. But within the Bundesliga, it's peculiar. As was shown by Mike Goodman at ESPN, attacks in the Bundesliga are built to win contests in midfield and then move quickly toward goal. Defenses in the Bundesliga typically also focus on winning those midfield contests, and they offer relatively less resistance around the 18-yard box than defenses in other leagues. (Further pretty charts demonstrating these league effects can be seen in this OptaPro article by Michiel Jongsma.)

A typical Bundesliga match will see about 60 open field possession contests (tackle or interception attempts) in the center of the pitch (from one 18-yard box to the other). There are only 35-40 open field possession contests in this area in a typical Premier League game. However, that EPL game sees on average about 60 clearances and 7-8 blocked shots compared to only 45 clearances and 5-6 blocks in the Bundesliga. There is much more defensive engagement in the center of the pitch in Germany, whereas in the Premier League the primary locus of defense is around the penalty area.

Leipzig bucks the German trend and plays lots of defense in the defensive zone rather than higher up the pitch. Only one other club in the league (Mainz) has blocked a higher percentage of opposition shot attempts and the other top, pressing sides attempt far fewer clearances.

Now, these charts show that Leipzig is not playing excessively huge numbers of clearances or blocking shots with the stuck-in devotion of a Tony Pulis side. Other clubs in the Bundesliga have tried to muddy up games and defend defend defend when faced with the creative attackers of Dortmund or Bayern. From Darmstadt to Köln, these are not new ideas nor are they sufficient to a title challenge.

Pressing without the risks

Hasenhüttl's innovation has been to marry old-time deep defending to a modern, high-pressing and midfield-contesting style. Despite protecting the penalty area and blocking shots, Leipzig manage to press effectively in midfield.

It is an unusual and difficult combination to pull off. Especially in the midfield-focused Bundesliga, teams generally choose between keeping defenders back to block shots and pressing to turn over possession before the ball reaches the box. Leipzig is the only team that tries to and successfully executes both, with above-average rates of both shot-blocking and pressing.

The secret to Leipzig's double act is the unusual 4-2-2-2 formation favored by Hasenhüttl. In this setup, Leipzig fields two central midfielders in front of the back four and two strikers at the top, with the other two attackers functioning somewhat like a more advanced version of the shuttlers in a midfield diamond -- positions that appear to be halfway between central midfielders and wingers. This formation, pictured below, enables Leipzig to press in midfield without overcommitting defenders.

The Leipzig press differs from those of the established German powers in exactly the way you would expect: it's more defensive. The best place to win a turnover is in advanced positions, but to extend the press to the opposing 18-yard box requires taking some risks with the positions of your deeper-lying players. In the middle third of the pitch, Leipzig presses as effectively as anyone other than Bayer Leverkusen, breaking up about 45 percent of opposition possessions that begin in the middle third. But that press is not extended into the final third with the same sort of gusto.

A Leipzig match will often feature moments like the following, where a press is triggered and then retreats as the opposition pass the ball back to their defenders.

By sitting off rather than continuing to chase the ball, RBL sees some loss of potentially dangerous attacks, but maintains its defensive solidity.

This tendency also reveals itself statistically. The following graphics show what happens when a team's press fails — when the opposition either keeps the ball for more than three good possession actions or executes an attacking move into the penalty area. For most pressing teams, it is understood that sometimes the press will be broken and you will need to defend in dangerous areas. Leipzig does not accept that exchange.

Against Dortmund, teams that get through the press regularly break toward the 18-yard box, down the wing or even the center. RBL throws up a brick wall and allow their opponents to pass it around at the back if they want.

Meet Naby Keita, a one-man show in midfield

Indeed, despite all the dogged and well-structured defending, there really is beauty in RB Leipzig's play. And that beauty is mostly provided by one man, central midfielder Naby Keita.

Attacking effectively in a 4-2-2-2 requires midfielders who can either weight a pass crisply into feet in traffic or beat defenders one-on-one in the open field. Keita specializes in both. His runs have become the stuff of memes, and deservedly so.

To quantify Keita's production in midfield, I developed a statistic for ball progression in midfield. This counts passes that take the attacking move at least 10-15 yards toward goal compared to where the ball had been over the last three actions (less progression required nearer to goal), and it counts runs on the ball that beat an opponent and progress the ball a similar distance.

By this number, Keita initially shows up in the top 10 in the Bundesliga, but his 4.25 progressive actions per 90 minutes remains behind creative heavy hitters like Thiago Alcantara and Kevin Kampl, the league's top two with over 5 per 90. However, Keita's skill is not merely to progress the ball, but to do so through the crowded middle of the pitch.

Here we compare Keita with Alcantara. While the Bayern playmaker moves the ball more, he does so mostly with distribution to the wings, while Keita's progression drives right through the heart of the opposition defense.

Keita averages just under two progressive passes or runs through the central zone per match, the most in the Bundesliga by a good margin. Next in line with 1.2 to 1.5 central progressions per match are Dortmund's Ousmane Dembele, Schalke's Nabil Bentaleb, Bayern's Franck Ribery and Xabi Alonso, and Keita's teammate Emil Forsberg.

Keita, and to a lesser extent Forsberg, make beauty from Leipzig's pragmatism. The team's careful, diligent, structured defending forms the foundation on which Keita and Forsberg must work. With the forward players mostly making sure to keep bodies central and prevent fast counter-attacks, RBL's creative players need to thread needles or take out defenders with dribbling skill. They need to do that without breaking the side's defensive shape, too. Keita's creativity and aggression on the ball enable Leipzig to be more than just another small side riding its defensive strength to average results.

So if you do watch RB Leipzig this season, key on Keita. Watch what he can do. But also appreciate the way Hasenhüttl has drilled his side to press without taking unnecessary risks and the careful movement of the defenders who almost never let a runner in behind. The reason RB Leipzig may win the Bundesliga title this year is the club's ability to support dynamic, progressive attacking play and a midfield press with a defense as difficult to penetrate as any that Tony Pulis has dreamed up. To appreciate the full scope of their quality, you also have to see how good they are at the boring stuff.