Liverpool's Record With and Without Lucas
After Lucas Leiva made a very impressive eight tackles, four interceptions and twelve ball recoveries in Liverpool's 3-1 win at Leicester City, there was lots of online chatter from Kopites suggesting that the Brazilian might finally be returning to something like his best form, which occurred prior to his anterior cruciate ligament injury in 2011.
Tweets like this one were soon doing the rounds after the match:
https://twitter.com/lfc_family/status/540216552688078850
I’m always wary of reading too much into with/without stats, as there are so many other factors to consider, and the above tweet only covers this season so is a very small sample. Looking at Liverpool's league form since 2009/10 though, it's impossible to deny that the team has performed a lot better on the whole when Lucas has played.
I chose Rafa Benitez' final season as my starting point for this comparison, as it was the first year where Lucas started more than thirteen league games, and so could be said to be an established component of the Liverpool first team.
Here are the figures, and remember they are for the league only.

The main thing to notice is that the team earns 0.3 points per game (or eleven across a full season) more when Lucas plays.
It's surprising to see that there is a greater improvement up front than at the back though, as I would've expected the reverse to be true when you consider that Lucas has been the club's only defensive midfielder for most of this timeframe. Perhaps his team-mates feel they have more freedom to attack when they have Lucas behind them, and they don't have to worry about tracking back quite so much?
As the above period includes the managerial talents of Benitez, Hodgson and Dalglish, I thought I'd finish with a look at the Rodgers era specifically.

I didn't expect to see that Liverpool's improvement with Lucas would be greater for the Rodgers era than for the last five years as a whole, not least as he played in all six of the Reds' defeats in 2013/14. But as you can see, that is indeed the case.
If I had more time, I'd look into how many shots Liverpool take and allow with and without Lucas, but I can at least point you in the direction of this site that does have this data for Reds' players this season (though not including Lucas at present): http://footballintheclouds.blogspot.co.uk/p/liverpool-11v11-on-pitch.html?m=1
As rumours continue to circulate that Lucas has been told he is allowed to leave in January, it seems fair to say that his recent form, plus the figures here, suggest that this might be a mistake on Brendan Rodgers' part.
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