When Gary Cahill joined Chelsea from Bolton Wanderers on January 16, 2011, many believed the club had acquired the perfect partner to play for years to come alongside John Terry in Chelsea’s centre of defence. Cahill, described by former Chelsea manager Andre Villas-Boas as having “immense technical attributes and fantastic pace as well”, had been the Bolton captain and was even beginning to move up the pecking order for the English national team.

However, David Luiz had already been brought in from Benfica a year earlier. Would John Terry be retiring at the end of the season? Had Branislav Ivanvoic or Ashley Cole fallen out of favor, so much that Chelsea would be employing one of their three centre backs in a wide position? The short answer to these questions is no.

While Luiz has featured 28 times in the league for his new club, Cahill’s appearances have been limited mostly to cup games. With Terry facing 2 more games out after being found guilty of racially abusing Queens Park Rangers defender Anton Ferdinand, the newly formed partnership of Cahill and Luiz will remain intact for the time being. Following that however, it is widely expected that Terry will regain his starting role, sending Cahill back to the bench.

Although Chelsea has probably exceeded even the most optimistic fan’s expectations this season, there is a case for sending Luiz, and not Cahill, to the bench when Terry returns. And so, this article takes a look at that position and compares the stats of David Luiz and Gary Cahill in their time together at Chelsea.

Overview

The chart shows that Luiz has played nearly twice as often as Cahill, both in terms of appearances and total minutes. Not surprisingly, both players have only been used twice as substitutes, because defenders almost always play the whole game.

Defending

The above graphic highlights that Cahill is 15% more effective (66% versus 51%) in terms of winning ground 50-50 balls. However, it should be noted that while Luiz has played nearly double the minutes of Cahill, he has been involved in nearly six times more ground 50-50 situations (173 to 35). In terms of aerial 50-50 balls, Cahill wins the ball 70% of the time, with Luiz winning them on only 58.5% of occasions. The pair is nearly identical in terms of tackling success. Luiz holds a slight edge at 87% to Cahill’s 86%. Luiz has about four times more interceptions than Cahill, while also being dribbled past five times more often. Amazingly, Cahill has not made a defensive error in his time on the pitch with Chelsea (a stretch of more than 14.5 full games), while Luiz has committed two such errors. Loss of possession statistics show that Luiz loses the ball about once per game (every 88 minutes), while Cahill goes 328.5 minutes on average without losing possession.

Passing and Goal Attempts

The passing and goal attempts chart shows that Cahill is 5% more accurate (88% to 83%) with his passes than Luiz. Cahill has also contributed 3 goals to Luiz’s 2; an astonishing statistic considering the large disparity in minutes played. Cahill has only taken 10 shots to score his goals, while Luiz has taken 18. This gives the players chance conversion rates of 30% and 11%, respectively.

Verdict

While there is no questioning John Terry’s place as captain and leader of The Blues, what’s certainly up for debate is who should be his partner in the centre of Chelsea’s defence. As mentioned, David Luiz appears to have a stranglehold on that position. However, this decision appears to be without merit. Gary Cahill is significantly more effective in nearly all defensive aspects of the game, winning 50-50 balls on both the ground and in the air at a greater rate than Luiz (15% more on the ground, 11.5% more in the air), while being dribbled past much less frequently. Additionally, Cahill loses possession less often and makes fewer defensive mistakes than Luiz. Although Luiz intercepts the ball more frequently, this is likely due to his over aggression; the same aggression that plays a large role in his ineffectiveness in other defensive areas. Moreover, Gary Cahill is a more accurate passer, completing an astonishing 88% of them, while also contributing more goals and converting a higher percentage of his chances than Luiz.

Roberto Di Matteo should be praised for the job he’s done at Chelsea. He won the Champions League last year and currently sits atop the standings in the Barclay’s Premier League. This is a testament to the fantastic players he’s brought in and putting those players in the proper position to succeed. However, in the case of David Luiz and Gary Cahill, he’s made a mistake; a mistake that he will likely never have to address should Chelsea continue their success.