A few years ago I sat in the stands at CenturyLink field in Seattle to watch a meaningless friendly between Seattle Sounders and Chelsea. These MLS friendlies against European teams on preseason tours amount to little more than exercises in marketing, and really, that game was no different. The Sounders got beaten 4-2 by a mix of Chelsea’s youth team players and big names trying not to pull any muscles. Every once in a while, though, there were glaring reminders of the gap in quality between the two sides. On that occasion, a lot of those reminders happened to come from Romelu Lukaku. Lukaku and his game both seemed larger than life as he bodied MLS starting center backs to the tune of two goals in 63 minutes and then left the field when it felt like he was just getting started. Obviously the stage of the performance warranted more than a grain of salt, but he gave the impression that he was something out of the ordinary. Fast forward to 2015, and Lukaku has strung together two consecutive 15 goal seasons in the Premier League, been to the World Cup, sold for 35 million Euro and is now leading the line for Everton. Though he’s certainly hit some highs over the last two years, this year has gone less smoothly. With Everton struggling and Lukaku bearing a greater attacking burden, he has produced only 7 goals so far, down to 0.28 NPG90 from 0.53 last year. He’s come under some considerable scrutiny for his play this year, and people are now praising Jose Mourinho’s genius for letting him leave Chelsea and banking the transfer fee. But before we label Everton’s record signing a flop less than a year on, it’s worth wondering whether this criticism is warranted, and what is responsible for Lukaku’s dip in form. Separate entirely from Lukaku’s own performances, consider how much has changed around him at Everton. Last season, nearly 80% of Everton’s midfield minutes were played by Ross Barkley, Gareth Barry, James McCarthy, Leon Osman, and Kevin Mirallas. This year, injuries have hampered Barkley, McCarthy, and Osman to varying extents. Osman has ceded minutes to the inconsistent Muhamed Besic and while Mirallas is still contributing, Everton have struggled to find a consistent option on the other wing, where Gerard Deulofeu caught on last year. This season has left Lukaku playing in front of a midfield in flux, whose performance isn’t matching the level it reached last year, and whose inconsistency has forced him to change roles depending on the circumstances. He also suffers from the same affliction as Mesut Ozil: a large price tag. Similar to Ozil, Lukaku’s performances have been colored by the expectations of supporters eager for constant brilliance now that their club has finally paid for a star. While Everton’s struggles as a team have contributed to Lukaku’s dip in performance, Lukaku has certainly dealt with his own drop in form. Last year, Lukaku’s conversion rate of 14.9% put him in the 83rd percentile among 178 forwards and midfielders who played at least 900 minutes. This year he’s converting only 8.6% percent of his shots, which would have put him squarely in the 50th percentile last year. On the other hand, his rate of shots on target has dropped by only four percentage points, suggesting that his conversion dropoff might be the result of some bad luck. We can examine this in a little more detail by mapping Lukaku’s shot locations. This is something that I and other writers on the site have used to break down in detail the shooting performance of a player or a team. In Lukaku’s case, it becomes abundantly clear that his goalscoring form from last year relied on shooting often and precisely from inside the box. Indeed, all 15 of his Premier League goals came from within the penalty area. This year, however, his shot volume is down from dangerous areas, and more of his shots come from the right side, where he’s more likely to be shooting on his weaker foot. His on target rate from these areas has also suffered. This seems to indicate that Lukaku’s struggles run a bit deeper than just bad luck in the form of regression to the mean. While this trend isn’t encouraging, it looks a little different in the context of Everton’s shooting as a team. Lukaku’s own shot charts mimic those of Everton, whose accuracy and volume from within the penalty area has dropped off this year. Viewed in this context, Lukaku seems to be suffering more from Everton’s attacking dysfunction as a team than an individual inability to generate and finish chances. Romelu Lukaku may not be on fire the way he was last season, but his teammates aren’t helping, and he may take some time to settle into a full-time role as the top striker at a Premier League club. Though some of Lukaku’s struggles are real, panicking about his development now seems very premature. He’s shown flashes where he looks impossible to stop, and his recent Europa League performance rightfully drew a comparison to Marshawn Lynch. It’s easy to forget in the midst of his third season seeing significant minutes in the league, but Lukaku only turns 22 in May. I’m confident that the best is yet to come.
In examining football statistics, sometimes there’s more information packed into a number than a few digits can convey. For instance, Zlatan Ibrahimovic has taken 77 unblocked shots and scored 16 goals, but these numbers don’t contain all the information we would want to know to determine his skill as a scorer or his goal threat when shooting. They don’t tell us where the shots come from or how often he converts a particular kind of shot. This is where a visualization can be extremely useful. Inspired by some of the work that Kirk Goldsberry did for NBA basketball, I collected shot data for 5 top footballers and made shot charts for each one. This post will be something of a test for how compelling the results are. First, a bit of explanation. The size of the hexagons on each chart represent the number of shots taken from within that zone, while the color represents the percentage of those shots which have been on target. The numbers over each hexagon correspond to the number of goals scored from each area. Zlatan Ibrahimovic The first thing to point out on Ibra’s shot is that he has a shot from well within his own half (on target nonetheless), which seems very much in keeping with the insanity that is Zlatan. Next time I imagine that shot will be finding the back of the net. The chart shows that Ibrahimovic takes quite a few shots, not all of which are from particularly dangerous areas. He does, however, gets his shots on target reasonably well from more dangerous areas. A good comparison for his chart is probably Cristiano Ronaldo, another high volume shooter who isn’t afraid to pull the trigger from distance. Cristiano Ronaldo, as the chart shows, will shoot from anywhere. Given his swerving shot, he’s probably the player you want shooting from range, but his chart shows that his on target rates in many areas suffer from his volume and his overall rate is sunk somewhat by his shot selection. He certainly scores a lot of goals, but this chart makes you wonder if some of it might be a result of sheer numbers in terms of shots taken. Luis Suarez is another player that fits in as a comparison for these two. Suarez’s chart reflects the kind of season he’s been having. His total volume is similar to Ibrahimovic, despite missing the first 5 games of the season through suspension. Even with the number of shots he takes, his on target rates from anywhere around the penalty area are consistently high. Suarez shoots from distance, but he really makes his money from 18 yards or closer. For a high-volume shooter, Suarez picks his shots a little more carefully than Zlatan, and certainly more so than Ronaldo, and given his form, it’s hard to question the results. Sergio Aguero If not for Suarez’s insane season, Aguero would probably be considered the in form striker in the Premier League. His chart makes for very different viewing than the previous three. He’s missed several games due to injury, which drives his total shot number lower than it might be if he had been fit all season. His chart still illustrates, though, how different his role is from all of the other players charted so far. Aguero relies much more on his finishing ability in the box than creating his own opportunities from distance. The location of his goals reflects this as well. His on target rate is extremely high inside the box. It suffers only when he shoots from acute angles on the left side of the box, where he would be mostly shooting with his non-dominant foot. Lionel Messi Messi has played fewer league minutes (due to injury) than any of the above players so far this season, so his sample is somewhat limited. He’s not a high volume shooter compared to the likes of Ronaldo, but he takes quite a few shots per 90 minutes played. The distribution of these shots, though, looks a bit more like Aguero’s than any of the other players. This matches the image of Barcelona’s style. Messi often scores his goals by arriving to meet a squared ball at the end of one of Barca’s signature passing moves, and most of the time these kinds of opportunities fall right around the penalty spot. If it wasn’t already clear, this chart illustrates just how effective he is in this role. With the caveat of the smaller sample size, Messi has the highest on target rate of the group. There are certainly more things to say about these charts, and more patterns to find, but this is mostly a pilot run for this method of visualization. In the future I’d like to adjust the on target percentage scale to be relative to average rates from different positions, but unfortunately I don’t have those data yet. If you’d like to see someone specific charted, or have feedback or ideas for future versions, please let me know on Twitter or by commenting. Data Notes The data consist of unblocked shots from domestic league matches up through January 18th. The data gathering was done by hand, match by match, using match reports from Squawka.com, which means it’s more likely that I committed an error with a shot or two than if I had access to a database of shot locations.