In coaching circles, there’s often a theory that if you win your battles you’re more likely to win a game. Being stronger in the air and smashing into opponents one-on-one is a reflection of a team that’s more likely to win a game. But do the numbers bear that out?
A recent example sets the scene nicely. After Eintracht Frankfurt’s 2-0 defeat at Bochum, there were some interesting post-match comments made by the visitors’ head coach Oliver Glasner.
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“Bochum involved us in many duels,” mused the Austrian. “Overall, we didn’t manage to counter it. We couldn’t prevail and didn’t let the ball run fast enough. For that you need mental freshness, that wasn’t there today. Only 40 per cent won duels are not enough.”
The numbers from that game — taken from Statsbomb via fbref — don’t quite match the figure quoted by Glasner, but the point remains the same. In total, Frankfurt were engaged in 53 aerial duels, winning 37.7 per cent of them. Of 20 occasions they were engaged one-vs-one by a Bochum dribbler, they successfully tackled them just four times.
For context, 53 aerials is the 14th most from the 81 Bundesliga games played so far this season. The duel win rate of 20 per cent is the eighth lowest by a team in a single game this season, and the aerial win rate isn’t much better, the 20th lowest out of 162 team performances.
Clearly, Frankfurt were outmuscled on the day, impacting their ability to get into the game. The match was skewed heavily by Danny Blum’s third-minute goal for the hosts, but Frankfurt barely threatened in the first half and only really kicked into gear with 30 minutes remaining.
Their xG total for the game sits at a decent 1.76, but that’s boosted by a first-half penalty, with Goncalo Paciencia’s effort saved by Manuel Riemann. Bochum on the other hand were far more dominant, creating plenty of good-quality chances which culminated in them sealing the victory in the 92nd minute via former QPR striker Sebastian Polter.
Zooming out and looking at a wider sample can be more indicative compared to looking at the figures in one specific match. Definitions here are important, and while “duels” are a fairly common term throughout football media, what actually are they?
Let’s get technical. In Opta parlance, a won ground duel takes into account any tackle made (both successful and unsuccessful are considered, as the latter sees an opposition move disrupted even though it doesn’t regain possession for the tackler’s team), a successful take-on that isn’t overrun out of play, a clean smother by a goalkeeper when challenged by an opponent or any foul won that doesn’t take place during an aerial duel.
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On the flip side, a lost ground duel considers all failed take-ons, dispossessions, fouls conceded (again, not during an aerial duel) and challenges lost when the tackler is easily outmuscled by the player in possession of the ball.
The formula for aerial challenges is, thankfully, a little more straightforward. The player either gets their head to the ball or wins a foul for a won aerial duel, or loses out and commits a foul for a lost aerial duel.
Looking at all duels combined in the Championship and the Premier League across multiple seasons shows that on average, teams that win more duels win more games. The figures in the table below of course are pretty blunt — they don’t control for the quality of sides playing in games, the type of duels taking place or the location of them — but they perhaps do give some credence to the theory that winning battles wins games at a very high level.
The effect of winning duels is more pronounced in the Premier League than it is in the Championship, perhaps due to more physical teams in the Championship lacking the requisite technical qualities to capitalise upon the disruption caused by winning a duel, whereas if a team in the Premier League is blessed in both a physical and technical sense, they can better leverage those situations.
Breaking down those duels further, it’s indicative that the type of duel has different effects between the Premier League and the Championship.
Winning more ground duels than the opponent sees a team win more often three per cent of the time, whereas in the Championship there’s a five per cent difference. In the Premier League though, aerial dominance brings greater rewards than in the Championship.
Football, though, is all about balance, and tables like this should be taken with heavy a pinch of salt. A team that reads this analysis and in their next game packs their starting XI with six-foot bruisers may physically dominate the possession, but not have the technical smarts to capitalise on having won the ball back more often.
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Going back to a single game example again shows this. Take Manchester United’s game against Sheffield United in January at Old Trafford. The home side dominated the duels, winning 23 of 28 aerial duels and 49 of 77 ground duels, some of the highest rates in a Premier League match in 2020-21.
Overall though, Manchester United failed to create much, putting up 1.09 xG from 16 shots to Sheffield United’s 0.96 xG from just five shots, with the visiting side clinching a 2-1 win. The average xG of a Manchester United shot was just 0.07, extremely low and indicative of Sheffield United being well organised and forcing the home side into speculative efforts from range.
And the goals that won the game for Chris Wilder’s side tell us about the importance of duels not occurring — not just them being won or lost. The first goal was a free header from a corner for Kean Bryan (29), who is unmarked when the ball comes into the six-yard box…
… and beats David de Gea in the air.
The second came from Oliver Burke (14) having too much time in the box and firing home practically unchallenged, helped by a deflection from Axel Tuanzebe. Various United players are slow to react, with Bruno Fernandes (18) the only one attempting to win the ball back.
Overall, it’s important to win your duels — in an attacking sense to gain ground, and from a defensive perspective to prevent the opposition from easily progressing the ball upfield. It’s not the be-all and end-all though, as highlighted above, and further research that doesn’t treat all duels equally in terms of importance or type could bring to light more actionable insights on what being weak or strong in duels means for a team tactically.
(Top photos: Getty Images; design: Sam Richardson)
