A Statistical Preview of Celtic’s Champions League Opponent Rosenborg

Check out the preview of Celtic from a Rosenborg perspective at our sister site, KroneBall.

When I started writing about analytics and Norwegian football a few months ago on KroneBall with Christian Wulff, one of the things I was pretty confident about was that Rosenborg would steamroll their way to another league title this season. When I was able to get data from the season before, the Trondheim club had an expected goal difference of about 30 better than the club with the next highest total and finished 15 points better in the table than second place Brann. While they failed to make it past the qualifiers for both the Champions League and the Europa Leauge last season, there was not much to suggest that any club would be challenging Rosenborg come March.

However, that has not been the case through 17 games this season in the Eliteserien. While Rosenborg does sit at the top of the table, they are only 5 points ahead of second place Sarpsborg. They have the third best expected goal difference in the league, behind the very impressive Sarpsborg (with a budget of roughly €4,000,000 and a stadium with a capacity of over 4,000) and underachieving Lillestrom. You could certainly claim Rosenborg are fortunate to be in first.

Celtic and Rosenborg are very similar positions in the European football landscape. They are both “big fish in small ponds”, having much greater resources than the rest of the clubs in their domestic league. However, comparing Celtic’s SPFL campaign last season to Rosenborg this year could not be more different. Celtic were never really troubled in Scotland on their way to a treble while Rosenborg are anything but comfortable slightly over half way through the Eliteserien. A better comparison would probably be current Valerenga manager Ronny Deila’s last year at Celtic. Aberdeen certainly gave Celtic a scare that year, but the gulf in resources helped Celtic see off the Dons and take the title. Rosenborg will be able to address their weaknesses in the summer transfer market and likely win the league again, while their title competitors will likely lose their best players over the summer.

Bendtner xG Map

Rosenborg hoped to further cement their position in Norway and make their way to the group stages of at least the Europa League, if not the Champions League by signing Niklas Bendtner. While Bendtner’s name may certainly be known, he has not been all that Rosenborg had been hoping for so far. He has 6 goals thus far in the league and is fifth in the league in xG with 4.95 and 0.41 xG per 90. However, for the money Rosenborg are paying for him, Bendtner was expected to bring much more. Despite Bendtner playing about 400 minutes more, Matthias Vilhjálmsson and Milan Jevtovic have scored 7 goals and Vilhjálmsson has a higher xG per 90 of 0.50.

In the league so far, Rosenborg manager Kare Ingebrigtsen has had Bendtner much higher up the pitch than we have seen him traditionally in his career. Bendtner does his best work in the box, using his physicality and strength to cause opposing back lines trouble. When he is able to get shots off this year, we see on his shot map that 72% of his shots come from the danger zone in the box, where you are more likely to score. However, Bendtner is only getting off 1.9 shots per 90 minutes, which is not enough for a player of his stature, and more importantly of his wage bill. And with an xA total of 0.99, “Lord Bendtner” is not offering much in terms of setting up his teammates with chances.


Meanwhile, Matthias Vilhjálmsson has only played in 825 minutes and is often coming off the bench for Rosenborg, but has more goals, scores them at a faster pace with 0.76 goals per 90, has a similar xG at 4.57 and a better xG per 90 at 0.50. Yet, Bendtner started over Vilhjálmsson in both legs of Rosenborg’s fixture with Dundalk. It was Vilhjálmsson however that came on to score the fixture’s winning goal in extra time for Rosenborg to advance and secure their place with Celtic. If Ingebrigtsen continues to start Bendtner over Vilhjálmsson and plays him in a similar role that he has all season, he might be doing Celtic an unintended favor.

One player Celtic will have to keep a close eye on is attacking midfielder Fredrik Midtsjø. The 23 year old Midtsjø has the highest xG+xA+xSA, or xGAS (tee hee hee) of 7.92 (xG 1.57, xA 4.99 highest at the club, xSA 1.36). He has a xGAS per 90 of 0.50, 4th best at the club. If you were to compare him to a Celtic player, Stuart Armstrong seems like a decent comparison (including good hair game). He is capable of creating his own shot, but he is more often creating for his teammates with a great final pass.

Midtsjo KP map

In the first leg of Rosenborg’s fixture with Dundalk, Midtsjø was deployed by manager Kare Ingebrigtsen on the wing, where he is less effective in my opinion. Perhaps questionably (I am starting to sense a pattern here), Ingebrigtsen has done this a few times in the season and it often resulted in Midtsjø being less effective. In the second leg back in Trondheim, Midtsjø was played in his more effective central role and I would expect to see him there against Celtic. Scott Brown will have to work hard to keep Midtsjø.


Midtsjø will be a player Celtic will need to focus on when Rosenborg are on the attack, but the Norwegians will be missing perhaps their best playmaker against Celtic. Pal Andre Helland, who Ronny Deila said would “be a big loss”, will not be available for either leg due to injury. Helland has the second highest xA total at Rosenborg at 3.62, but has the same xA per 90 of 0.32 that Midtsjø has. Helland also has the second best xSA at RBK at 1.25. Rosenborg will need to find someone to step up in his place and fill the important role he has with the club.

With this injury and Bendtner’s lack of production so far this season, Rosenborg might be looking to keep things secure in the back, hit Celtic on the counter, and hopefully be within striking distance heading back to Trondheim for the second leg. Ronny Deila suggests as much when talking RBK and Celtic’s Champions League match-up, saying in an interview with the BBC “Their best skills in the team are defend and counter attack. That will suit them and that’s what they want to do in Celtic Park – they want to stay a little bit higher than maybe Linfield was doing.” The only issue is, the stats do not necessarily show that is what they do best. Rosenborg’s xG against is slightly better than average in the league, but worse off than 2nd place Sarpsborg, 4th place Brann, as well as mid-table club Odds BK.

Dashboard 1-4

Meanwhile, Rosenborg have the 2nd highest xG for in Eliteserien so far. Similar to Celtic in Scotland, teams in Norway often sit back against Rosenborg and they have to break down packed penalty areas. They do not often have to sit back themselves and try to counter domestically. Their defense has had some troubles this year, giving up 3 goals against recently promoted club Kristiansund after going up 2-0. RBK eventually got a late equalizer to save a point, but this is not the only instance they have shown defensive frailty.

Tromso currently sit second last in the league and have already sacked their manager this season, but they were able to beat Rosenborg thanks largely to the play of speedy Icelandic winger Aron Sigurdarson. The Rosenborg fullbacks have struggled much of theRosenborg Tromso.jpg year when trying to contain opposition with pace. I am an admirer of Sigurdarson, but Scott Sinclair is much more talented than he is. Heck, Johnny Hayes and James Forrest are likely more talented than Sigurdarson. Celtic would be wise to use the overwhelming pace available in their squad to exploit the trouble the Rosenborg fullbacks have with it.

If Celtic is at their best, they should get through Rosenborg and advance to the Champions League Playoff. Of course, random variance can see anything happen over two legs, but the pace and quality Celtic have should be enough to overcome Rosenborg. Perhaps the only question one may have is what, if any the off the field distractions at Celtic will have on the fixture. The xOpinions Yer Da has on the Green Brigade are definitely overachieving on Twitter right now.

With the early exits of Rangers and St. Johnstone from European competition this year, Scottish football supporters and pundits alike resumed the calls for the Scottish season to be played in the summer, such as Norwegian and other Nordic football leagues do. Yet, those calls were not as loud after Swedish club Malmo were dumped out of Europe last round. None of these calls mentioned Rosenborg failing to qualify for both the Champions League and Europa League last season, nor their struggle to get past Irish Champions Dundalk (who also, ironically, play Summer football) last round. There are changes needed in Scottish football, but there is not much evidence that Summer football is what is necessary, and Rosenborg this year show that.

This article was written with the aid of StrataData, which is property of Stratagem Technologies. StrataData powers the StrataBet Sports Trading Platform, in addition to StrataBet Premium Recommendations.

Identifying Possible Break-Out Players By Making League-Wide Comparisons

As I am writing this, Barrie McKay is being sold to Nottingham Forrest and former boss mckayMark Warburton for a rumored £500,000. When I read this, my thoughts immediately went to the video The SPFL Radar made of the compilation of key passes McKay made last season that one would expect would lead to a goal, but did not. Now, I have written countless words discussing the short comings of the strikers Rangers had last season and I will not add to that here. However, the video had me check McKay’s expected assist stats from last season, where I saw he had a 7.84 xA and 0.28 xA per 90. “Pretty good,” was the first thought that came to mind, but then I thought “compared to what?”

By now, most who have been following my journey through stats and Scottish football are probably familiar with terms and concepts like “expected goals” “expected assists“, and “goals per 90 minutes“. If you are not, check out those links above. There seems to be more acceptance of these ideas around Scottish football as time continues to pass. Well, I am about to throw a whole new concept at you. But you have nothing to fear, it builds on what we know rather than something entirely new.

We know expected goals is a better indicator of future success than things like shots or even goals, but it often can be a bit abstract. If I tell you that Adam Rooney had an expected goals of 10.60 in 2016-2017, you can surmise you could expect him to score around 10 or so goals based on his performance. Maybe he will overachieve and scorerooney, maybe he will underachieve and score less, but we could reasonably expect 10 goals. However, does that mean Adam Rooney had a good season? A bad season? A mediocre season? Expected goals by itself does not tell us much when it comes to a player’s performance compared to the league.

While baseball does not have the hold on Europe that it does on North and Central America, one cannot deny that it was an early adaptor of analytics and stats. I have discussed this before when applying the concept of the age curve to the SPFL and I am going to borrow from baseball here again. Baseball has come up with some stats in Runs Created and On-base Plus Slugging that they have realized are better indicators of performance than traditional stats like Batting Average, which certainly sounds like a familiar phenomenon to what football is going through now. They report these stats in traditional percentages, but they also compare a specific player’s stats to the league’s average in that stat with stats like wRC+ and OPS+.

These baseball stats gave me an idea. I would certainly like to know how a striker’s expected goal stats or a midfielder’s xA stats compares to the rest of the league. I decided to apply the same methodology baseball stat nerds apply to wRC+ and OPS+ to football. Now, perhaps proving we surround ourselves in an echo chamber on Twitter, I contacted Rangers Report to see if this idea was crazy or if it made sense. He let me know he was working on something similar with goals and borrowing the ice hockey stat of Goals Above Replacement. He has written about this and you should read it.

To do this, I first needed to determine the average expected value I was going to use. I also decided to use xG per 90 numbers so minutes played would not skew the numbers. For all “attacking” players (as classified by Transfermarkt) that played at least 400 minutes and took one shot last season, the average xG per 90 was 0.18 in the SPFL Premiership (perhaps tellingly that was the Non-Penalty Goals per 90 minutes for that same group as well).

Now that we have an average, we can compare your favorite player’s xG per 90 with the average. We divide a players xG per 90 by the average and then multiply that by 100. Heart of Midlothian v Glasghow Rangers, 1st, February, 2017This gives us what I am, tentatively, terming as a player’s xG per 90+. If you have an xG per 90+ of 100, you are average, at least when it comes to your xG per 90. Every number above 100 is a 1% better than average, anything number below 100 is 1% below average. Let us use Adam Rooney again as an example, last season Rooney averaged a 0.33 xG per 90. We divide 0.33 by 0.18 and multiply by 100 and we get an xG per 90+ of 140, meaning he was 40% better than the average “attacker” in the SPFL last season. Got it? Ok, let’s look at some numbers and see what we can get from them.

xG p 90+_NPG p 90

The above chart compares attackers from the SPFL Premiership xG per 90+ and Non-Penalty Goals per 90 who have at least played 400 minutes and taken a shot last season, and we see many names we would expect towards the top. Dembele, Griffiths, Sinclair, Moult, Boyce, etc. However there were some things I noticed and first was Esmael Gonclaves, aka Isma of Hearts. The Portugese striker was brought to Tynecastle in January and with the controversy that surrounded the Jambos and manager Ian Cathro in that time, Isma put together some impressive stats during a time when not many impressed in maroon. In fact, Isma had a xG+ of 219.7 (meaning he was 119% better than the average striker in the SPFL last season), which was second among SPFL attackers. Combine that with a very impressive Goals per 90 of 0.41 in his time last season, and one could think that given a full season at Hearts, Isma could be among the top scorers next season with that performance. Of course, all this is dependent on Isma not wringing Ian Cathro’s neck on the touchline, which is not a given.

Something else I noticed on this graph was Alex Fisher. The recent Motherwell signing had a xG per 90+ of 145.6 (or he was 45.6% better than the average attacker last season). He also had the highest Goals per 90 of this group at 0.66, but finishing can be fickle and can fluctuate up and down. However, we see Fisher having similar xG per 90+ numbers as Liam Boyce, Louis Moult, and Adam Rooney. Last year, Fisher only played around 800 minutes for Inverness Caley Thistle. We would expect him to get more playing time next year, seemingly as the replacement for Scott McDonald for the Steelmen. While he may see some regression in goal scoring, if he can continue these good xG per 90+ numbers, we can guess he will be able to add more goals for Motherwell.

In addition to using this metric to compare players and their xG, we can also compare players xA as well. We calculate “xA per 90+” the same we do for xG. We take the league average xA per 90 of 0.13 and divide a player’s xA per 90 by that average and then multiply it by 100. In this chart, we see the xA per 90+ and Assists per 90 for every SPFL Premiership player who has played at least 400 minutes and have one assist.

Dashboard 1

Perhaps surprisingly, we see Leigh Griffiths with the highest xA per 90+. I have discussed Griffiths being more than a goal scorer before and we have more proof here that Griffiths is more than a poacher, with Griffiths xA numbers 212% better than average with an xA per 90+ of 312. We also see Ryan Christie second in this metric, with an xA per 90+ of 229. Numerous people have been very impressed with Christie’s time at Aberdeen last year, and the winger will be back at Pittodrie on loan this season. With such impressive numbers, Christie could be  replacement for Johnny Hayes the Dons are looking for this season.

Another surprising name we see right next to Christie is Motherwell’s Elliot Frear. The English midfielder arrived at Fir Park in late January and put in some impressive frear.jpgperformances to help the Steelmen avoid relegation last season, and his xA per 90+ of 220.8, third highest in the SPFL. With a full season with the ‘Well, if Frear can replicate these numbers, he could put together a great season with Motherwell.

Finally to bring everything around full circle, we again look at Barrie McKay. When we see his xA per 90+ numbers, we see he had a 109 xA per 90+. That means McKay was 9% better than the average player in the league when it comes to xA, which was 17th best in the league. With this new metric, I am hopeful that stats like expected goals and expected assists will become more than abstract concepts and a tool we can use to compare players contributions, like McKay’s, the rest of the league. I am also open to suggestions on the name or any other comments you have about it.

This article was written with the aid of StrataData, which is property of Stratagem Technologies. StrataData powers the StrataBet Sports Trading Platform, in addition to StrataBet Premium Recommendations.