Five lessons from Europe
With the first leg of the Champions League round of 16 done and dusted, here are five things we've learned:
1. Italian sides are vulnerable to width
When he destroyed Maicon at White Hart Lane late last year, Gareth Bale was something of a trendsetter. With his blazing pace, Bale showed that Italian clubs seem to have a real problem facing tricky wingers. Aaron Lennon's run and pass in the San Siro last week opened up Milan; Douglas Costa's superb strike away at Roma was probably the best goal of the first legs, while Arjen Robben and Franck Ribery were Bayern's main threats against Inter last night.
Serie A is home to very few top-class wingers, which means that Italian sides tend to play very narrow. Inter, Milan and Roma have all frequently played 4-3-1-2 systems this season -- the action takes place in the center of the pitch, and although the full backs receive little protection from their midfield, they often don't need it as the opposition isn't playing any wingers either.
However, when Italian sides play 4-3-1-2 in Europe, the fullbacks' lack of support becomes a real issue. Sometimes, as in the cases of Bale or Lennon against the two Milan clubs, it's simply because the full back needs extra help against a particular player. On other occasions, like Bayern's visits to Roma and Inter, the opposition fullbacks are free and combine with the wingers to create two-versus-one situations down the flanks.
In short, tactics that work well in Serie A aren't so successful in Europe -- and that's partly why Italian clubs recorded three home losses.
2. Barcelona is relatively poor away from home in Europe
The loss to Arsenal was Pep Guardiola's seventh away knockout game in the Champions League as a manager -- and, incredibly, he hasn't won any of them. Seven games is a relatively low sample size, and away games against the best 16 sides in Europe are always very difficult contests. However, considering that we're talking about a manager who has won 73 percent of his career matches, and a side that some consider to be among the greatest in history, it's a surprisingly poor record.
Some of those non-wins have been insignificant -- the run includes a 1-1 draw at Bayern, for example, when Barcelona had won the first leg 4-0. But Guardiola has often got his tactics wrong away from home. At Chelsea in 2009, his side was below par and fortunate to get through to the final. At Stuttgart last year, Barca was vulnerable to the opposition's wingers and was flattered with a 1-1 draw, then at Inter in the semifinal Guardiola used Zlatan Ibrahimovic as a central striker when pace and movement were preferable.
Now, for two years in a row, Barcelona has collapsed late in games at the Emirates. What's more, in this season's group stage, Barca stumbled to draws at minnows Rubin Kazan and Copenhagen. Guardiola's men remain the competition's best side, of course, but on their European travels they are definitely beatable.
3. Meaningless yellow cards can add up
Barcelona's Gerard Pique, Lyon's Michel Bastos, Copenhagen's Zdenek Pospech, Roma's Jeremy Menez and Milan's Gennaro Gattuso (even before the postmatch head-butt scrap with Joe Jordan) all picked up their third yellow card of the competition, meaning they will be unavailable for the second leg of this round.
Players receiving suspensions for accumulating yellow cards continues to frustrate. At last year's World Cup, Golden Boot winner Thomas Muller was banned from the semifinal after having picked up two yellow cards in five games. Two mistimed challenges in 450 minutes of football shouldn't cause a player to miss such a huge game, though at least there was an "amnesty" on yellow cards after the quarterfinal stage in that tournament.
UEFA rules mean that yellow cards never "expire" in the Champions League. Three yellow cards at any stage result in a suspension, which means a player can miss the final having picked up just three bookings in 12 matches, a card every four games. Dani Alves missed the 2009 final in this fashion.
Regardless of the rights and wrongs, the rules are in place -- and players have to abide by them. Looking back, it is amazing how unnecessary some of the cards are from earlier in the competition. Menez's tackle on Bayern's Anatoliy Tymoschuk in the final minute of Roma's 3-2 win was pointless, as was Pique's lunge on Vitali Kaleshin, also in the 90th minute, at Rubin Kazan in September. At the time these cautions seemed irrelevant, but a few months on, they're responsible for teams being without key players. It's worth managers reiterating this point throughout the group phase.
4. French players are on fire
All four goals Tuesday night were scored by French players -- one apiece from Bafetimbi Gomis and Karim Benzema and two from Nicolas Anelka. Those strikes mean that more Champions League goals this season have been tallied by French players than by any other nationality: 37.
That's a surprising statistic when you consider the French national side's problems. From the 23 players who were called up for the game against Brazil earlier this month, only four had scored at the international level. For the starting XI in the humiliating defeat against Belarus late last year, only one player, Florent Malouda, had scored international goals. Anelka won't be a part of the national team any time soon, and Gomis and Benzema can be underwhelming. But French players clearly do have goals in them.
5. The ties are finely balanced
From eight ties, only one second leg (Chelsea versus Copenhagen) will start with a side having more than a one-goal advantage. This is partly due to the format of the competition, since the first legs of the knockout stage all feature the group winners away from home. So it stands to reason that the first legs will be close matches as (generally) the better side is away from home and can hold its own.
In a way, the results were largely as expected. Copenhagen was the weakest runner-up and the only side to lose by two goals, while Arsenal was the strongest runner-up and the only home side to win.
On the whole, it was a very good round of Champions League action. Milan versus Tottenham, Arsenal versus Barcelona, Roma versus Shakhtar and Inter versus Bayern were all excellent games, while only Marseille versus Manchester United finished goalless. Since last year, the second round is split over four separate match days (rather than two), meaning fans are able to watch twice as many games as before. For a round like this, we should be very grateful.
Michael Cox is a freelance writer for ESPN.com. He also runs zonalmarking.net.