04 April 2013

Liverpool's Aerial Prowess

There were a couple of comments in the Villa match infographic post which suggested I look at Liverpool's aerial stats. It's a valid concern, given that Liverpool have often struggled against aerially dominant strikers, whether Benteke, Carlton Cole, Jon Walters, or Olivier Giroud, seemingly more susceptible to crosses and set plays.

Let's start with headed goals scored and conceded.

Through 31 matches, eight of the 40 goals (20%) Liverpool have conceded were via headers: 0-3 West Brom (a), 0-1 Chelsea (a), 1-2 Stoke (a), 0-2 United (a), 2-1 Arsenal (a), 0-1 West Brom (h),1-1 Spurs (h), and 1-2 Spurs (h). Five of those eight (62.5%) came from set plays: at Chelsea, at Stoke, at Arsenal, against West Brom, and the second against Spurs.

Last season, 10 of the 40 goals Liverpool conceded came from headers (25%), and six of those ten (60%) were from set plays. So, not much difference. Except that Liverpool have already conceded the same number of goals through 31 matches as they did through all of last season, but I think that's a slightly different discussion.



Conceding 20% of its goals via headers puts Liverpool just above the league average – which is 19.6%. Eight teams have conceded a larger percentage of goals via headers: United, Tottenham, Chelsea, Everton, Swansea, Stoke, Newcastle, and Wigan. However, only Newcastle and Wigan have conceded more goals in total than Liverpool in that group.

At the other end of the pitch, Liverpool scored eight headed goals out of 47 in total last season. This season, Liverpool have scored seven headed goals of 59 in total. Skrtel against City, Suarez at Everton, Suarez at Chelsea, Agger against Southampton, Gerrard against Villa, Agger at QPR, Downing at Wigan. Only Gerrard and Downing's were from open play.

Unsurprisingly, this puts Liverpool near the bottom of the league for headed goals scored.



Only Sunderland and City have a smaller percentage of headed goals. But Rodgers' side isn't built around players who score headed goals, which is why Carroll's currently plying his trade at West Ham.

As for aerial duels, Liverpool have won 414 of 784 attempted this season. Liverpool have won more aerial duels than the opposition in 22 of the 31 league matches; Liverpool's record when winning more aerial duels than its opponent is 10W-7D-5L (1.68 ppg) and 3W-2D-3L (1.22 ppg) when they don't.

The player-by-player breakdown:



Not included: ┼×ahin (12/23), Reina (5/5), Jones (1/1), Suso (1/2), Assaidi (0/1), Cole (2/5), Carroll (2/2).

Liverpool's forwards obviously don't contest many aerial duels, which is also evident in the headed goals total. None of them are very good at it, and it's not the way Rodgers' teams play. Last season was different. Carroll won 152 of 236 (64.4%), Kuyt won 32 of 86 (37.2%). Incidentally, Carroll's currently leading the league in aerial duels won per match, with 10.2 (174 of 266; 65.4%). This seems like a good time to again remind that Liverpool only scored 47 goals in total last season.

At the same time, opposition teams seem to be playing a lot more aerial passes against Liverpool this season. Skrtel featured in far more matches last season, but only contested 97 aerial duels (winning 78; 80.4% successful). Agger won 44 of 69, Carragher 14 of 23, Johnson 19 of 31, Enrique 9 of 16. Only Carragher's total for this season is below last season's, which makes sense as he's started half the number of matches as last season. Every other regular defender has attempted more aerial duels this season. And every regular defender had a higher successful percentage last season.

But the midfield's total, especially Lucas', stood out to me. Maybe it's just because the match at Aston Villa is fresh in the memory, where he committed five fouls in the first half, struggling with the long balls played to Benteke when the striker dropped off the center-backs.

So I thought it might be helpful to compare him to other out-and-out defensive midfielders in the league, with some suggestions taken via Twitter yesterday.



The best defensive midfielders, at least in this regard, have a better success rate than Lucas, who only wins 50% of his aerial duels. This is admittedly worrisome. But not many beat Lucas for volume.

Going by WhoScored's statistics and position classifications, very few central midfielders have won more aerial duels per game than Lucas: Fellaini (who barely counts for this comparison because of the way Everton use him in attack), Javi Garcia, Bradley Johnson, Leon Osman, Gareth Barry, and Stephane Mbia. And that's about it.

This is one area where Liverpool could improve over the summer. Even if Henderson and Allen are "better" backups for Lucas than Liverpool had last season (*glares at Spearing and Adam*), both are even worse defending against headers.

A similar comparison for other center-backs compared to Skrtel and Agger:



It's safe to assume that an aerially dominant center-back tops Liverpool's priorities for this summer's spending. Skrtel's become out of favor, as has Coates, and Carragher's retiring. Even if Rodgers sees both Wisdom and Kelly as future center-backs, he'll need one or two, if not three, more central defenders.

But neither Agger nor Skrtel are that far behind comparable defenders. Even considering this season's woes and his regression from last season, Skrtel remains near the top in aerial duel success rate, while Agger is better than the likes of Vertonghen, Kompany, Ashley Williams, and others.

If you're curious, here are the league-wide team stats, listed in order of current league position.



It's no surprise to see Stoke lead the division, by some distance. Nor is it a surprise to see Roberto Martinez's Wigan at the bottom. Liverpool are close to the bottom in volume, but above the league average in success rate (the league-wide average is obviously 50%).

There is room for improvement at both ends of the pitch. Liverpool's attack under Brendan Rodgers will never live and die by its headers, but Liverpool also might not be as bad in the air as we're led to believe, and should improve in defense as both Wisdom and Kelly mature (and the latter returns from injury).


All stats via Squawka, WhoScored, or StatsZone.

5 comments:

Anonymous said...

http://www.eplindex.com/25322/liverpool-problem-target-men-stats.html

I wrote something similar to this earlier in the season.

Basically my hypothesis was that since Liverpool have the ball a lot, the opposition feels the best way to attack is through a hoof followed by gathering the second ball. This is backed up by the "target men" I looked at averaging way more aerial duels attempted against Liverpool than against others. (Even the Stoke boys).

Also, Agger and Skrtel have both regressed in defending against burly forwards I believe.

PS: The captchas on this site make me feel dumb.

nate said...

Neat, wish I had seen this yesterday; would have saved me some research.

Interesting to see that Agger's aerial duel win percentage has gone up from 60% to just over 62% in the last two months. Tough to know without the January duel win/total duels numbers to compare, but would think that if he continues similar improvement over the last seven matches, he'll get up to 64-65%, the percentages from his best seasons (last season, 09-10).

Randomly, despite Walters' and Jones' success, Liverpool won more aerial duels than Stoke in both meetings this season.

Also, appreciate the fact you put a link to my Oldham review in that piece.

Anonymous said...

No problem, the fact that someone else thought Liverpool were kind of soft aerially actually prompted me to look into it.

suley said...

Hey Nate,

thanks for that really great info. really appreciate the time and effort.
To be honest I really thought we were alot worse then that.

I do wonder though where we stand vs the rest of the league in terms of goals conceded through counter-attacks or crosses followed by a shot(not necessarily headers)

There has got to be a reason our defence looks so brittle even at the best of times. I just dont buy into the argument that our defenders are just having a bad season. I'm no tactical expert but I do wonder if Rodgers system lends itself to exposing our defence much more and just doesnt suit itself to certain defenders.

basstunedtored.com said...

Suley

I have the stats for counter attacks here:

http://basstunedtored.com/2013/04/05/crosses-counter-attacks-and-confirmation-bias/

Although we haven't conceded the most goals from them we have conceded the joint highest proportion of the total faced.