As you may know, Barcelona square off against a familiar face in the Champions League semifinals: their old coach, Pep Guardiola.
Guardiola led the Blaugrana to European glory twice, among many other successes. Now, Barcelona must exploit Pep's weaknesses - their old weaknesses - to get through.
One of these is a slightly underwhelming record in Europe.
Now don't be confused: Pep's away record in Europe is good. It is about average even when you compare it to other top managers of the past few decades.
Facing against European elite is tricky stuff, so it's not surprising that his teams would drop a few. However, compared to his sterling overall record, it is not quite of the same magical level.
Let's take a look through the years.
In the 08-09 season, Pep's Barcelona didn't win any of their three away games in the knockout rounds, scoring only one goal per game.
In home ties and the final, played in neutral ground, Barcelona outscored opponents 12-2, conceding both goals in one game which was won 5-2.
This suggests Barcelona were clearly superior to the other teams in general, but struggled to make this superiority count in away matches.
That season, Barça even lost their away match in the qualifying round, 1-0 against Wisla Krakow. They won at home, 4-0.
The 2009-10 Champions campaign was similar. Barcelona won exactly one match away from the Camp Nou, including the group stages: 2-1 against Dynamo Kyiv. After that it was four draws and a loss. At home, Barça won every match but one.
It wasn't just the dichotomy in results, but in performances. Barcelona drew away to Stuttgart and Arsenal in the knockout rounds, only to smash them at home by a combined score of 8-1.
Internazionale opened up a 3-1 lead in the away leg, and this time Barcelona could not reverse the tie, winning only 1-0 at home.
The 2010-11 campaign was a little different. Initially, the pattern was familiar: draws away against Rubin Kazan and Copenhagen in the group stage, and a 2-1 loss against Arsenal in London in the round of 16. However, Barcelona would win their next two away matches: 1-0 against Shakthar and 2-0 in a famous victory over Real Madrid.
Barcelona started the season in dominating form, finishing the group stage undefeated and with a +16 goal differential. The knockout rounds was less awesome, though. Barça did down Bayer Leverkusen 3-1 in Germany, but considering the Blaugrana won 7-1 at home, it could be considered a sign of a disparity. Barça played a drab 0-0 draw against AC Milan in Italy, but won rather comfortably by 3-1 at the Camp Nou. Chelsea won by a small margin in London, 1-0, but it proved vital. Barcelona were winning for the majority of the return leg but, due to the away goals rule, were still forced to chase goals. The end result was a 2-2 draw and elimination.
After taking a sabbatical for a year, 2013-14 was almost a reversal. Bayern, Guardiola's new team, only lost one game in the group stages, and it was at home.
In the round of 16, Bayern defeated Arsenal away 2-0 and was comfortable to draw 1-1 in Munich. In the next round, a more familiar pattern: Bayern drew at Old Trafford but defeated Manchester United 3-1 at the Allianz Arena. In the semis, something somewhat unexplainable happened. Bayern lost the first leg away to Real Madrid 1-0, but actually worsened, losing 4-0 in Munich.
Had the pattern changed?
This season says no. Bayern's sole loss in the group stage was away to Manchester City. And in the knockout rounds, the pattern was extreme. Away to Shakhtar, Bayern could only draw 0-0, but in the return fixture, the Bavarians crushed the opposition by a score of 7-0. Against Porto, again Bayern struggled in the first leg away, losing 3-1 to unfancied Porto. In the return, again Bayern fans filled the stadium and again their team demolished the opponents, this time by 6-1.
In the knockout rounds, Bayern have a goal differential of 13-1 at home but 1-3 away. Sure, this is a small sample size, but the difference is extreme.
In football in general, the importance of home-field advantage is dwindling. The idea of traveling to a far-away ground, to a country no one on the team was familiar with, is quaint. There are less surprises as games are beamed across the world. and less culture shocks as teams are much more international.
Away fans are more present at stadiums now, travel is more comfortable, and referees have perhaps better oversight.
Still, home teams win about 40% of matches while away teams win only 30%, the remaining 30% being draws.
If we look at Pep's failures in the Champions League, what's interesting is only one time has he lost both legs. It's likely he will at least draw if not win one of the matches, particularly the home match.
In all three eliminations, however, he lost the away leg, which interestingly, came first each time. His teams only scored one goal across those three matches.
Pep Guardiola is one of the greatest coaches ever and Bayern Munich, even somewhat shorthanded due to injuries, is a team replete with talent. Eliminating them will be anything but easy.
However, if this is to be accomplished, history has shown that winning at home in the first leg is the best method.
Bayern are in a position of some psychological vulnerability after being eliminated by Borussia Dortmund from the DFB Cup on penalties. Not only that, but Robert Lewandowski might miss the first leg due to an injury he picked up during that match. Franck Ribery will probably miss the first leg, though there's a chance he could be in the second.
Meanwhile, Barcelona are in great form, having won the past two games by a combined 14-0. Jordi Alba might not be 100% and Jeremy Mathieu is sure to be out... but other than that, Barça are about as healthy as you can expect to be at this stage.
This suggests Barcelona need to strike early, and often, if they want to go through.
Full Stats, Guardiola in UCL Knockout Stages