You often hear former pros and managers talk about the importance of "settled lineups," and it makes sense. If the same guys are playing together, they develop chemistry and an understanding that makes them more effective. They'll also have a better grasp of whatever tactical system their manager wants to play.
But that's also something of a self-fulfilling prophecy. A team that is doing well, at least relative to its goals for the season, will tend to not make too many changes under the old maxim "if it ain't broke, don't fix it." As such, I decided to look at the top six teams across Europe's big five leagues and work out what percentage of league minutes the 11 most-used players spent on the pitch. Now, there are obviously a bunch of factors that account for these numbers, which is why they're best used in conjunction with other data.
A team that suffers injuries will score lower, as will one that signs several starters during the January transfer window. You would expect clubs competing in Europe or going on long cup runs to score lower as well; more wear and tear on players means more need to rest or alternate them. Then there are the managers, who ultimately decide who plays. Some believe in squad rotation more than others, and some have been fiddling with their formations all season (I'm looking at you, Roberto Mancini). Others will play the same system and same crew wherever possible. That said, looking across Europe from this vantage point yields some interesting results.
It probably won't surprise anyone that Leicester City had the most settled team in the Premier League (and ranked second across the top sides in the Big Five). The same 11 guys have been on the pitch for a whopping 86.2 percent of the Foxes' total league minutes this campaign. That suggests that Claudio Ranieri has benefited from a lack of injuries and suspensions to this point, that Leicester haven't been deep in the cups and that they're not involved in European football, all of which are true.
More surprising, perhaps, is that Tottenham rank second in the Premier League's top six and fourth overall out of the teams on this list. Mauricio Pochettino's side clocks in at 81.3 percent, which is certainly notable, given that they reached the last 16 of the Europa League and the fifth round of the FA Cup.
Still, the single most settled team in Europe on this list is Napoli, who are second in Serie A and come in at 88.2 percent. That's a very high number when you consider that they played 10 games between the Europa League and the Coppa Italia and that Maurizio Sarri is in his first season at the club, which implies he might have needed more time to find his best XI. It's also very much an outlier relative to the other top six teams in Serie A, who collectively average 72.2 percent.
Also scoring high are smaller teams enjoying exceptional seasons. Clubs such as Hertha Berlin (up from 15th to third in the Bundesliga, at 81.1 percent), Caen (from 13th to sixth in France, at 77.5 percent) and fellow Ligue 1 side Nice (11th to third, at 75.1 percent). It confirms what you might expect: These are teams with no European football who have avoided a rash of injuries and are performing well, so their managers rarely change the team.
What about the other end of the table? Rennes had the least settled lineup (64.1 percent), and you can chalk that up to injuries, a poor start and a coaching change, with Rolland Courbis replacing Philippe Montanier. Monaco, at 68.3 percent, has also been hit relatively hard by injuries.
Inter are at 68.8 percent, but here, it's down to the manager. They have had some injuries, sure, but Mancini has changed players and personnel on a regular basis (just five men have started more than two-thirds of Inter's Serie A games) in the elusive search for decent performances. The same applies to some degree to Unai Emery at Sevilla (68.1 percent), though unlike Mancini's, his team has had to play an additional 19 games (and counting) between European competition and the Copa del Rey.
The really surprising club in this mix is West Ham. They are currently fifth in the Premier League, just one point from a Champions League place, and by all accounts, they're having an exceptional season, up from 12th last year. Yet their 11 most frequently used players accounted for just 69.7 percent of league minutes, with just six players starting more than two-thirds of the Hammers' league games.
Part of this is down to some wheeling and dealing. Modibo Maiga, Kevin Nolan, Matt Jarvis, Nikica Jelavic and Mauro Zarate all played for them this season, and all are now elsewhere. By the same token, Sam Byram and Emmanuel Emenike joined midseason, and they have had plenty of injuries as well. Yet whatever the reason, voluntary or forced, Slaven Bilic has changed his lineup almost continuously this year without West Ham's form suffering. That's a credit to the manager.
Looking at the numbers suggests that different rules apply to bigger clubs. Paris St. Germain (70.9 percent), Juventus (70.5) and Bayern Munich (73, higher than the other two, but they've played fewer minutes overall, and they're the lowest in the Bundesliga top six) rank on the low end. Although injuries again play a part, a lot of it likely has to do with the fact that they have bigger squads and can better withstand them.
The decision to rest a player is often as much about his substitute as the player. If Giorgio Chiellini has a knock for Juve or Blaise Matuidi could use a breather for PSG, you've got Andrea Barzagli or Adrien Rabiot ready to step in. If you're Ranieri at Leicester and Wes Morgan or Robert Huth are less than 100 percent, then you're looking at Marcin Wasilewski, which isn't quite the same thing.
On its own, this metric can tell you only so much. You need context and additional data to draw broader conclusions. Ideally, you'd combine this with other metrics and make adjustments based on injuries and suspensions. I'll leave it to the analytics types out there to take if from here if they see value in it.
Still, this highlights at least one potentially important issue: The average across the list is 74.3 percent. Broadly speaking, Sarri at Napoli, Ranieri at Leicester, Pochettino at Spurs and Pal Dardai at Hertha have had the unusual luxury, relative to their colleagues, of playing the same guys over and over again.
They might not find themselves in that situation next year.