If an enemy's enemy is a friend, Liverpool against Arsenal can seem the friendly rivalry among the Premier League superpowers. The Merseysiders have had more-fractious relations with Chelsea, Manchester United and Manchester City. The Gunners have seen each of those three raid the Emirates Stadium for players and have a historic foe in Tottenham.

They may regard each other as the lesser of the evils. Indeed, when Liverpool beat Chelsea in the 2005 Champions League semifinals, two of the first...

Arsene Wenger is a creature of habit. In two decades with Arsenal, certain patterns and trends have emerged, whether it's lifting the occasional cup or finishing fourth.

Until last season, a back four was another staple of Wenger's management. However, back in the spring a desperate roll of the dice saw him introduce a new-look three-man defence. The change in formation sparked an upturn in Arsenal's fortunes, as they embarked on an impressive run that culminated in them lifting the FA Cup at Wembley.

However,...