In the UEFA Champions League knockout phase, a commonly held belief is that playing away in the first leg offers a significant disadvantage. However, statistical analysis of all matches in the knockout rounds since the competition’s inception in 1992/93 suggests that this notion may be flawed. In fact, the distribution of teams advancing from the first leg shows no clear advantage between those playing at home first and those playing away. The numbers reveal that, overall, approximately 50% of teams that play away first advance to the next round, the same percentage as those who play at home first.
However, there is an important consideration in the round of 16 that alters this dynamic. In this stage, the runner-up of each group plays the winner of the other group at home first. This creates a scenario where weaker teams, often fortunate to even make it to the knockout stage, face top-tier clubs such as Barcelona, Real Madrid, Bayern Munich, Juventus, PSG, or Manchester City. These teams are typically strong enough to win their group and often dominate in the round of 16. As a result, these lopsided matchups are common, and in these cases, the team that finished first in the group (and thus plays away first) has a significant advantage.
Looking at previous seasons, the round of 16 has frequently been marked by uneven matchups. In the 2017/18 season, for instance, teams like Porto and Liverpool, or Basel and Manchester City, were seen as mismatches. Similar scenarios occurred in the seasons that followed, with weaker teams being drawn against much stronger opponents. This pattern leads to the conclusion that, especially in the round of 16, the team that finished first in the group playing away first has an edge in the tie.
Statistically speaking, teams that play away in the first leg tend to progress with a high probability, particularly in these imbalanced matchups. Therefore, while the overall statistics might suggest a roughly equal chance of progression for home and away teams, the unique structure of the knockout round means that in many cases, the team playing at home first has little to no chance of advancing.
The conventional belief in the advantage of playing at home in the second leg stems from the idea that both teams tend to be cautious in the first leg, with the away team focusing on defense. This often results in tight matches with relatively low scores. However, the second leg presents a different dynamic. If the away team wins the first leg with a narrow score, say 2-1, they enter the second leg in a more comfortable position. A 0-0 draw in the second leg would suffice for them to advance. On the other hand, the home team needs to score at least one goal without conceding to progress, which is often a difficult task.
The home team, having already lost the first leg, is forced to adopt a more attacking strategy in the second leg. While they still have the advantage of playing at home, the need to score puts them in a vulnerable position. If the away team scores an additional goal, the home team’s chances of progression are severely limited. Therefore, the team that won the first leg at home has a psychological and strategic advantage in the second leg, making it harder for the away team to mount a comeback.
In conclusion, while there is no clear overall advantage between playing home or away first in the Champions League knockout stage, the structure of the competition particularly the round of 16 favors teams that finish first in their group and play away first. The statistical evidence suggests that the away team, especially in these uneven matchups, is more likely to advance, making the initial belief in the “away first” disadvantage increasingly outdated.
