Jurgen Klopp: Led Dortmund to their first Champions League Final in 16 years
Tactics, as a whole, is something of a grey area in football, even though it tends to separate the decent coaches from the special ones. It's generally because the unpredictable nature of football can turn the game on its head in a matter of seconds.
There are all kinds of determining variables which can undermine hours or even days of preparation for a game—red cards, injuries pre-match or during the game or having 72 percent of possession and still not winning.
But a shift in tactical focus occurred last week, which reinforced the point as to why managers spend so long working on their tactics with their side. What the viewer would have witnessed had never been successfully accomplished by any coach other than the creator himself.
It takes months of preparation and training, but it seems that Pep Guardiola's 'six second ball retention' strategy is no longer exclusive to the Spanish coach.
Indeed, because as Borussia Dortmund coach Jurgen Klopp demonstrated in the Champions League semifinal, Guardiola is not the only coach with a tactical nous.
Dortmund were rampant, and it wasn't just their four-goal talisman Robert Lewandowski who was taking the plaudits. Mario Gotze, Ilkay Gundogan and Marco Reus taunted the Real Madrid players, showing great desire and work rate to cause Los Merengues all kinds of problems.
To witness a team with such attacking mentality, filled with exuberance and high-octane pressing, was a joy to behold as Dortmund crushed Real Madrid 4-1 at the Signal Iduna Park last month.
Klopp's players were determined and fired up, and you could see it every time they chased down their opponents; they wanted the ball back and this would have been practiced time and time again. The Dortmund players made Real Madrid, a team usually so confident on the ball, feel uneasy in possession and that was the German's objective.
It's more of what Klopp orders off the ball that is essential to his success, and the method of retaining possession has been key to Dortmund's unexpected rise to prominence.
Contrast that to Chelsea, who are said to be extremely interested in bringing the highly-rated coach to Stamford Bridge, where inviting pressure from their opponents before winning the ball back is a continuous tactic throughout their last few managers.
The Blues are set up as a similar model to Klopp's favored 4-2-3-1 approach, although Reus is more of a second striker while Juan Mata drops deeper as the main playmaker. Nevertheless, the former Mainz coach would not have to initiate a shake up of the team's formation, with the option to have two deep lying midfielders and wingers providing support to the main striker.
Chelsea's current crop of players does boast a significant amount of energy, with the likes of Ramires and John Obi Mikel possessing the kind of stamina which is envied by many. As seen in the Champions League Final, they rarely tend to close down opponents when they receive the ball, instead waiting in an area where they can intercept a pass, for example.
This could be changed if Klopp was able to bring Ilkay Gundogan with him from Dortmund, so that Ramires would chase down the ball and the German international could then play the killer pass into the attacking trio of either Mata, Oscar or Eden Hazard.
On the subject of attacking support, Klopp encourages his full backs in the shape of Marcel Schmelzer and Lukasz Piszczek to overlap the wingers Jakub Blaszczykowski and Mario Gotze and aid them when pressing forward. Chelsea has a similar setup, with Cesar Azpilicueta and Ashley Cole often seen racing down the touchline and in this sense, nothing would need to change.
However, perhaps the arrival of Klopp would mark the end of using the likes of Ramires and Oscar on the right wing, when their respective positions are centre and attacking midfield.
If you take a glance at the current Dortmund side, every player, with the exception of emergency left-back Kevin Grosskreutz, is used in their favored position, giving them the opportunity to play to their optimum level.
Not to say Ramires or Oscar are ineffective on the right hand side of midfield at present, but to position them where they are used to playing allows them to play with confidence, and viewing it psychologically, it could be something that gives Chelsea that extra bit of quality that other sides are missing.
What is clear is that there is a tendency from both Dortmund and Chelsea to play with a refreshing direct approach, especially on the counterattack. Getting the ball up the pitch to the target man and using the three playmakers around him is an effective tactic for both sides, and one that the 45-year-old would seek to instigate should he arrive in West London.
He's already displayed his tactical prowess and shown himself to be popular among his players and with the press, and with age on his side, there's no questioning why Chelsea would list Klopp as a candidate to the helm at Stamford Bridge.
Of course, with the talented coach about to lead Dortmund into their first Champions League Final since 1997, there's no guarantee Klopp would want to leave the club he joined five years ago.
If the opportunity were to come about, there is no doubt that Chelsea could do a lot worse than employing Jurgen Klopp as the man to take the club to new heights in European football.