During their time in the English premier league, the two managers have become closer. If you missed the past decade of men's soccer at the elite level, it would be hard to discern from a single Manchester City vs.Liverpool match which team was managed by an innovator in how to play.

As they have competed for all major titles, these two styles have merged and become something that the majority of clubs all over the world want to replicate. City has become a more aggressive pressing team over the last few years, whileLiverpool has become more possession oriented.

City has the highest possession in the league, we are not far behind. There are differences in our set up, but not as much as they used to be. Both teams want to win the ball back high.

It is easier for clubs at any level to build teams that play pretty football out of the back and aggressively thanks to the advancement of nutrition and fitness training, as well as the wider acceptance and reliance on the collection and analysis of video and data. The quality that mid-budget teams in top leagues can display using this style is extremely impressive, and there are more teams than ever before that play in a way that is commonly referred to.

There are very few true clashes of styles at the top level of the game because this has come at the expense of tactical variety. All of the teams in the top tier of financial resources attempt to execute on the same macro-level vision for how the game is supposed to be played.

There were a couple of fresh ties in the last few weeks.

The one side that has consistently bucked all these trends under manager Diego Simeone is Atlético Madrid, which chose to camp all of its players within 30 yards of its own goal in the first leg of its tie against Manchester City. Phil Foden got City on the board once, but Atléti persisted with its tactics in the first half of the second leg. They gave themselves a chance to progress to the semifinals, even though they had to open up to chase a goal in the final 45 minutes.

If the two teams faced each other in a tactical mirror match, the gap in form and technical talent would likely result in Atléti going down by much more than one goal.

It used to be quite common to see a team with top attacking talent trying to break down a perfectly organized Bunker at the highest level of the game. It wouldn't be very entertaining if most football matches played out like that, but in the current era of more homogeneity, it felt like a nice treat.

Atletico Madrid employed ultra-defensive tactics to hold Manchester City to a goalless draw, but lost 1-0 on aggregate in the Champions League quarterfinals. Getty Images

A similar pair of matches played out between the two teams, but with a bit more precision on the counter, which resulted in an even better result. The tie was finished with 34% possession to the other side and 16 shots to the other side.

According to Michael Caley's expected goals model, the Bavarians were the better side and unlucky not to progress. The Yellow Submarine's deep and organised defense frustrated their opponents into taking poor quality shots from outside the box. The team that was in control of the tie ended the 180 minutes with the same number of high quality chances from central areas inside the box as the team that was on the back foot.

Building around the players that fit your style

You can't have everything when it comes to player recruitment. It is possible to sign players with no real weaknesses, but it is also possible to build a squad with individual skills that complement each other, while also masking each other's deficiencies. The style of play used by Unai Emery maximized the talent of the players he had available.

In the middle of the park, there is a player who does not have the athletic qualities to succeed in a game against a quality team, but he does have the passing ability to create dangerous attacks from a very small number of opportunities. Although not a pressing machine, strikers such as Gerard Moreno are excellent technically. Samuel Chukwueze is not yet a consistent provider of goals and assists at 22 years old, but has the ability to create something out of nowhere off the bench.

They would have been humiliated if they tried to match the style of the other team. Emery created conditions where his players could be successful, and that trio capitalised on their best opportunity of the second leg to win the tie.

Villarreal clinched a late goal against Bayern Munich to win 2-1 on aggregate, proving the Yellow Submarine's patient approach to upsetting top opposition. Marcio Machado/Eurasia Sport Images/Getty Images

These two quarterfinals are similar to games where two evenly matched sides are throwing haymakers at each other, as they both have a significant advantage in talent and the other has to figure out how to get the best out of the players they have to stand any chance.

Football is at its best when there is variety, and we have been presented with two completely different semifinals. The first leg of the Manchester City vs. Real Madrid match was a back-and-forth thriller with multiple goals for both sides. It is intriguing to see that a team that thrives on attacking quickly into open spaces has to contend with a team that can stifle Europe's best with their low defensive block.

The Reds were kept off the board until the 62nd minute, when they were able to get on the board with two goals, but despite being kind enough to give the Reds a test run, they fell 2-0. A team that is likely to set up with a similar deep position, albeit with a bit more quality to play out of trouble and execute counterattacks, will be the team that will face the Reds.

If every team plays the same style of football and the game becomes tactically homogeneity, many fans would prefer to see these defensive sides break out of their shells and show a little bravery. If the only reason you watch the game is to see goals, you should take a trip to YouTube. In 20 minutes, you can binge hundreds of them. Great attacking football is satisfying because of the presence of great defensive football.