Category Archives: Transfers

We Should Have Seen It Coming: Evaluating Jamie Vardy Against the EPL’s Elite Strikers

I did some updates to my interactive transfer evaluator – the stats are all the same (2014-2015 season stats) but I cleaned up some code and listed a few players under multiple positions to get it ready for the January window. I thought a good way to introduce it to my new followers was to show a demonstration with the EPL’s biggest story of the first half of the season: Jamie Vardy.

A quick discussion of the method behind the transfer evaluator: my model’s predictions are a function of player stats (aggregated to the team level) and a “team strength” coefficient. To evaluate how well a player would do on a new team, I remove the player currently in the position, subtracting his stats, and then substitute the new player, adding his stats. The model then recalculates the probabilities for all 38 games, adds the expected values up, and gives the new points. It’s a fun interactive app, and was a lot of fun to build so I’m pleased to see how much people have enjoyed it.1

So I wanted to test what my model thought of Jamie Vardy compared to the EPL’s elite strikers and on some Big ClubsTM. It found that many of these teams would have done well to sign Vardy last summer – the results are presented in the graph below.

Vardy

Keep in mind all of this was done before this year happened.  Vardy’s record-breaking goal streak isn’t included in this model, only the underlying stats from 2014-2015 (for strikers these are mostly shots, shots on target, shooting accuracy, and probably some passing stats).  He’s an improvement over Wayne Rooney (+4 points for United), Christian Benteke (+3 for Liverpool), Olivier Giroud (+2 for Arsenal), and a small improvement over Romelu Lukaku at Everton. He’s also only a 1 point downgrade over Diego Costa and Sergio Aguero, and a 4 point downgrade over Harry Kane following his amazing season. Being an improvement over some great strikers, and basically break-even against world-class strikers like Costa and Aguero is pretty remarkable, and one could easily argue that only being a 4 point downgrade over Harry Kane given his amazing season is strong as well.

The Benteke finding is the most interesting one to me: Vardy was reportedly available for somewhere around £15 million, while Liverpool reportedly paid over £30 million for Benteke to score 4 goals in 14 appearances so far. My model would have identified Vardy as a better signing, and maybe Liverpool would have been the beneficiaries of the purple patch Vardy (and Leicester City with him) have gone through this season.2 With the margins being as thin as they are for the top 4, this knowledge could have been invaluable to Liverpool.

Other than Liverpool, my transfer evaluator shows him as a good backup for Aguero at Manchester City and Costa and Chelsea. City probably doesn’t need him with Bony as their #2 striker, but Chelsea would clearly have benefited from another striking option other than Loic Remy (especially given Jose Mourinho’s tactical nous that seemed limited to “We’re down a goal, replace a midfielder with a striker” for the first 15 games of the season or so). Distribution from Mahrez has been unbelievably important for Vardy, but Oscar/Willian/Hazard might all be having better seasons if they had Vardy to aim at.

The transfer evaluator clearly didn’t anticipate how big Vardy would have been this year, but it did recognize that he’s either an improvement or a decent replacement for many of the Premier League’s elite teams and did so before the season even started. Take it for a spin and see who your favorite team should sign for the second half of the season.






  1. I get 25 free “active hours” a month, and my Twitter followers used those up in 4 days this month. I’ve bought 500 hours to hold me through January 25 – hopefully that’s enough.
  2. This all assumes someone provides at the level Mahrez has this year, which is a big assumption. Even if he didn’t score as many goals, he’s still a 3 point upgrade over Benteke given the underlying stats. Although given the price, maybe Liverpool could have signed Mahrez and Vardy for the cost of Benteke.

Five Reasonable Transfer Targets for Leicester to get into the Champions League

I’ve been playing with my transfer simulator 1, trying to find some good signings for various teams and I figured I’d post some blogs about what I found. With Leicester City being in the news and some of the big models (including mine) predicting they have a chance at the Champions League, I thought I’d start with them.

The “rules” for transfer club are simple: I haven’t watched a ton of footage from some of these clubs, so I start by looking at my “Points Above Replacement” spreadsheets to identify growth opportunities.

Next, I look at top of the list of players identified as improvements and delete any players who I feel are unsignable. Reasons for this include “plays for a direct rival”, “would be too expensive”, “too old to buy”, or “plays for a bigger club and would be unlikely to move downward.” I also look at Transfermarkt to see what they say the player’s value is as a proxy for a lot of these things.

That’s about it – I’m pretty lax on position because I think my model sometimes identifies potential tactical shifts that would benefit a team by playing someone in a different role. With the description out of the way, here’s who I’ve identified for Leicester City.

Week 15 - Transfer Upgrades for Leicester City

All of these players are young and are likely within Leicester City’s buying range. I like Sonny Kittel a lot because he can play centrally or on either wing 2, and he’s a big upgrade over Drinkwater according to my model.3  He’s just recovering from a fairly serious injury though, so they may not want to take a chance on him. Depending on what you’re looking for, Magnanelli, Kacar, and Dabo are also improvements and are more defensive-minded which may be a better tactical fit depending on what Leicester is looking for.

The second player is Florentin Pogba, who’s a 3 point upgrade over Wes Morgan. He looks a little stronger in terms of offensive statistics, and is younger with a bigger upside. MOTSON thinks signing both him and Kittel gives Leicester City an extra 10 points over the season, or ~5 over a half-season.  In a season where 4th place is relatively wide open and small margins could matter, these are all decent signings at a reasonable price.






  1. The public version is currently down, but I’ll re-up the paid subscription to Shiny Server around December 20 when the transfer rumors get into full swing again.
  2. I always like players who can cover for other players, especially for teams with a limited budget
  3. Someone mentioned on Twitter that Drinkwater is pretty highly rated right now, and from the little I’ve seen I agree with this. The model likes all of these players over N’Golo Kante as well, but everything I’ve read lately says he’s playing too well to bench.

Replacing Coquelin – Prognosis and Options

Arsenal fans received some bad news for the team’s title chances when they found out Francis Coquelin is out with a potentially long-term injury. Without a lot of options in reserve, Arsenal fans are worried and have already begun to criticize Arsene Wenger for not buying a backup option for the defensive midfielder. Should Arsenal fans be worried? I want to look at the consequences of losing Coquelin for Arsenal, and potential replacements for him in the medium term and ways to strengthen the squad in the January window.

The first question is how badly will Arsenal miss Coquelin? He’s a key part of the team, and his backup is Mathieu Flamini who Arsenal fans don’t seem to rate highly at all. I broke out my Transfer Simulator to see how many points Arsenal could expect to lose with Flamini as a replacement for Coquelin, and Arsenal fans shouldn’t be too concerned.

Flamini

When I substituted Flamini in for Coquelin to my model, I only see a four point loss over the course of a season, which translates to a roughly 4% decrease in win probability in any given game for Arsenal. This isn’t too bad, although 4 points could potentially be a huge different given that Arsenal’s expected final lead over Man City is currently 5 points. A 2 or 3 point drop over the time Coquelin is out of action makes the title race a lot more competitive, so there is some reason to be concerned.Week 13-1 Predicted Final Table

The next step was to find suitable replacements for Coquelin in the January transfer window. Assuming Wenger wants to buy (which is a big assumption given his history, especially in January), how many options are there? Going back to my first cut at a Points Above Replacement (PAR) measure from a few months back, Coquelin is possibly Arsenal’s most difficult player to replace, offering them a ~4 point bump over the median player in my database (more than any other player in their opening day first team). 1PAR Arsenal

This matches Wenger’s philosophy that top players are difficult to replace, so he shouldn’t necessarily spend money just for the sake of spending money. If he can find a legitimate upgrade, then he should so do, but that’s going to be difficult for Coquelin.

Are there options though? I ran some of the big names, and came up short, and honestly they’re probably unrealistic for what Wenger would be looking for/willing to pay in January anyway. Even ignoring that, most of them weren’t an upgrade over what Coquelin brings to the table in terms of offensive and defensive production simultaneously. More offensive-minded players cost Arsenal valuable defensive contributions, and a lot of pure defensive-minded holding mids fell short by a shot  per 90 minutes over Coquelin’s contribution and didn’t offer as much in the passing department. To find options, I did two things.

First, I looked at my list of replacements that generated the graph above. Because I have all midfielders classified in the same group, most of the replacement improvements weren’t positional fits: the model wanted Arsenal to buy Franck Ribery, presumably because his offensive contributions somehow overshadow his defensive limitations in this case. However, I did find a couple of cases that were interesting here: Jeremy Toulalan and Etienne Capoue. They’re not great options – Toulalan because of his advanced age, and Capoue because he just recently transferred to Watford and might not be seeking a second move so soon, but they’re both basically break-even compared to Coquelin.

Second, I went to my multi-dimensional scaling project to find similar players. The full method is explained in another post, but the idea is that I use game stats to create a two-dimensional placement for all players in my database. From there, I can measure the distance between each player and Coquelin, with shorter distances representing more similar players. This generated a couple of other interesting leads for players, but strangely enough most of the most similar players were wingers, indicating that Coquelin’s contribution as a defensive mid isn’t what you’d expect.

Coquelin MDS

Fer and Vujicevic are fairly close to Coquelin in terms of stats and contribution, and interestingly are incredibly similar to each other. Capoue and Toulalan are very different from Coquelin but are very similar to each other.

I like each of these players because they’re all affordable and would likely be comfortable as a rotation option for Coquelin. All of them but Toulalan are reasonably young (ranging from 25-28),  which is good and fits with what Wenger would like to do. So what is the expected point contribution of each of these players? I ran them through the transfer simulator, and here’s what I found.

Coquelin Replacements

Toulalan, Capoue, and Vujicevic are all *slight* downgrades from Coquelin, while Fer is about a five point downgrade. Not ideal, but it demonstrates the difficulty of replacing someone like Coquelin and shows what sort of position Arsenal is in. Each player has their downsides (Toulalan’s age, Capoue made a recent move already, Vujicevic would be making the transition from a less competitive Eredivisie straight into a Premier League title race, and Fer is arguably a downgrade over Flamini), but this is where qualitative scouting would come into play. Fer is the youngest of the group: can he improve quickly? Would Vujicevic’s performance transfer well into the EPL from the Eredivisie?

There are options, but I couldn’t find a silver bullet to replace Coquelin. Arsenal has a difficult series of choices ahead of them, and many “ok” options but not any great ones. It may be the best option to ride it out with Flamini, hope he can be solid in the short-term, and think about finding a better option in the summer window or even re-balancing the squad to have some more flexibility in their midfield.






  1. Arsenal fans -you’ve already beaten me up over my rating of Bellerin here so you don’t need to do a second round

Manchester City’s Midfield Depth Problem

This week’s Manchester Derby was fairly uneventful, with City registering the first shot on goal for either team somewhere in the middle of the second half, and the game ending in a 0-0 draw. City was without two of their best attacking players (Sergio Aguero and David Silva), and it showed. To compensate, Manuel Pellegrini moved Yaya Toure up from his typical deep-lying midfielder/box-to-box role to a more attacking role behind Wilfried Bony, who would often come back deeper to link the defense to Toure in attack. From there, presumably the plan was for Toure to distribute the ball to Sterling and de Bruyne on the wing who would then either cut inside or cross the ball to Bony. I say “presumably” because de Bruyne usually either kicked the ball to the nearest Manchester United defender or as far as he could over the touchline, wasting the few opportunities City had to attack.

This plan worked relatively well up until the wingers got the ball, and as a City supporter I couldn’t have been happier with the Bony/Toure linkup. However, the American commentators focused quite a bit on how much City missed Aguero, and while he’s one of the best strikers in the EPL, I disagree that missing him was the problem. Running the quick numbers through my model, Bony as a replacement for Aguero is only a couple point downgrade over the course of a season. Missing Silva was the problem, and City needs a backup for him.1 Who can they get?

First, I looked at my “Points Above Replacement” spreadsheet, and confirmed the conventional wisdom: Yaya Toure and David Silva are both in the top 25 players in my database at their given position for Manchester City.2.  From the few players who were improvements, I looked for players who could play at least centrally in addition to their primary position as either a defensive mid or attacking mid, and I eliminated players who come from rival teams who would be unlikely to sell3. After these filters, I was left with what I consider six good options4.

Midfield Reinforcements Manchester City

The barplot shows the change in expected points for each of the six players I found as options for Manchester City. The best option according to my model is Swansea City’s midfielder Ki Sung-Yueng. He’s in his prime (he’ll be 27 in January), would be relatively easily buyable for a “big club” like Manchester City, and can play either as a defensive midfielder or more centrally.

The next best option, for me, is Milan Badelj. He’s the same age, and can play both centrally and as a defensive mid, and based on his history would be reasonably affordable to buy from Fiorentina.

Gary Medel and Daniele de Rossi are probably my least favorite buys on the list: both are older, de Rossi’s probably unbuyable and I’m not sure what sort of price tag it takes to buy a player from Inter Milan these days.

The other options are the young stars: Ilkay Gundogan, Marco Verratti, and Lorenzo Crisetig. Of the three, Gundogan’s price tag is probably too high and reportedly said “no” to Manchester United this summer. Crisetig is the biggest surprise on the list (my model likes him for Arsenal too), but he’s young with a big upside for me, and wouldn’t be too expensive as a speculative buy. I like Marco Verratti a lot, and PSG *may* need to sell someone if there’s any truth to the rumors that they’re going to buy Cristiano Ronaldo, and he could be a long-term replacement for either of the two aging stars so if he’s buyable I think City should pursue him.

To be clear, this is just a starting point. If I’m in charge at City, I’m surprised by how much the model likes Ki Sung-Yueng so I send scouts to every Swansea City game between now and January 1 and watch every bit of video I can get on him to see how well he’d fit the team’s style and how well he could slot in for either Toure or Silva. Same with Verratti, Badelj, and Crisetig. City’s depth could be their biggest weapon, but it was clear today that they don’t have a great second option for when David Silva is out and that could be what stops them from catching Arsenal.

 

 






  1. My model actually thinks Patrick Roberts would be a good replacement for him, but clearly Pellegrini doesn’t trust him as much as my model does so I’m operating under that assumption here.
  2. Yaya Toure is #16 in the box-to-box role, and Silva is #23 in the CAM role for Manchester City
  3. My model really likes Daley Blind as a replacement for both of them, but he’s obviously not an option
  4. Really five good options and Daniele de Rossi, but I’m such a huge fan of his I always like to add him when I’m talking box-to-box midfielders

Fabregas Doesn’t Work: Replace him with a Defensive Mid

Quick blog post here looking at Chelsea’s form today, and one of the big narratives has been Cesc Fabregas’s underperformance. While this may be true, I’d argue that the bigger problem is that he’s a poor fit for Chelsea in the role he’s playing.

I ran the numbers, looking at Points Above Replacement for Fabregas’s position in Chelsea’s lineup, and unsurprisingly most of the top 10 were pure holding midfielders, or at least more defensive minded midfielders.  Here’s the graph:

PAR Cesc Fabregas

Out of the top 10 options, Marco Verratti and Robbie Brady are the only two that aren’t known for playing deeper. Even if Fabregas plays well, he’s out of place in Chelsea’s lineup and they should strongly consider replacing him/selling him in January.






Europe’s Most Valuable Strikers

Today’s post is meant as a follow-up to my post from a week ago detailing each team’s best possible striking option.  In that post, I found that most teams’ best option was to buy Theo Walcott, which was a bit of a surprise but matches up with what Goalimpact says fairly nicely (and apparently received the same “huh…that’s odd” reaction on Twitter). As a reminder, here’s the main chart from that post.

Best StrikerToday I ran a new analysis, looking at each striker’s added value for each of the 20 EPL teams and calculated their points above replacement value over the 25th percentile. What I’ve found is that the PAR measure as I currently calculate it is very team dependent, which I think is useful in some ways, for example if you were trying to find a replacement player for your current striker you’d want to know who fits into your team best. However, it isn’t as useful for comparisons between players across teams more generally. So what I did was calculate the number of points each team would earn with each striker in the database, just like in my previous post. Then I found the striker in the 25th percentile would earn, and subtracted that value from each striker’s expected points in the database.

As an example, I calculated the average score for Theo Walcott across all 20 EPL teams, which was ~63.4 points. I then subtracted the striker at the 25th percentile (Deportivo’s Lucas Perez) who earned ~55.5 points, arriving at an overall PAR value of ~7.9 points. I repeated this for all the strikers across the league and here are the top 20 most valuable strikers in Europe.

PAR Strikers

Theo Walcott is at the very top of the list, Leo Messi comes in at #4, Zlatan at #5, and Cristiano Ronaldo at #11. There are a few surprises on the list, but a lot of it looks like you’d expect. One could take issue with individual ratings, but keep in mind these are based on expected statistics, shots on goal are included but not goals scored1 and based off of a model trained on EPL data so you’d expect some changes if this was done in La Liga or Serie A.

Also, it’s interesting to me that after Walcott, the next 7 positions are virtually tied, and then the last 12 are virtually tied with each other. Someone like Ronaldo who finishes his chances significantly above expectation could easily move up 5 spots or more, so I understand why he’s lower than one might think.

The other interesting thing to me is that Glenn Murray finished as the #1 option for a few teams, but didn’t make the top 20 overall. That tells me he’s a really good option for a few teams, and a fairly bad one for many of the others.

This is just the latest iteration of the PAR project. I’m really in an exploratory data analysis mode right now, so I’m open to any feedback people have on other ways to do this. Follow me on Twitter @Soccermetric.

 






  1. Including goals scored causes the broader model to overfit and and skews things in any number of ways for non-strikers.

Each EPL Team’s Best Possible Striking Option in One Chart~!

I’ve been working on spreadsheets of the value of every player for every EPL team, and it’s FINALLY done1 If you’re interested in the method you can read more at http://soccer.chadmurphy.org/methods/arsenals-room-to-improve/, but the quick version is that I calculate the number of points each team is expected to earn using a Random Forest model. Then I replace their striker with each striker in my database, re-running the Random Forest and calculating the new expected points. I sort them by number of expected points, and listed the top striker in this plot and plotted the number of points the team would be expected to gain with that striker. The plot is available below:

Best Striker

There are a couple of interesting things to note: first is the relatively low number of points each new striker would add to each of these teams. Theo Walcott would be a huge upgrade to Sunderland and Spurs, but the average gain is only 7 points. This could mean two things: most teams already have a fairly good striker, or strikers are generally overvalued in terms of their contribution to the team.  Or maybe I’m undervaluing how much 7 points is for one team to improve based on signing one player.

The second thing is how popular Theo Walcott is in this model. He’s the best striking option for 7 of the 20 EPL teams, which is remarkable considering he’s not considered a top tier elite striker. Lionel Messi was the next common best option, and was almost always in the top 10 choices for the rest of the teams, giving me a nice validity check on my model.  Bournemouth’s Glenn Murray was also really popular, which was surprising, although Messi was considered an upgrade over him for Bournemouth.

This was an interesting exercise, and is the first check on the way to my “Points Above Replacement” measure (PAR). Thinking about doing defenders next.

Follow me on Twitter @Soccermetric

  1. Each team takes ~300 minutes to run. Multiply that times 20 teams plus a couple extras for coding errors along the way/accidentally deleting files and just generally being sloppy…

Rio Ferdinand: “Arsenal or Liverpool Should Have Bought Ashley Williams”

One of the big stories today in England was Rio Ferdinand saying “Arsenal or Liverpool Should Have Bought Ashley Williams”. I’ve never thought of Ashley Williams as a top level defender like that, but I was running an analysis of Chelsea’s defending options for one of my followers and he showed up at the top of the list of potential John Terry replacements and as the absolute top Gary Cahill replacement. So I wanted to test Rio’s assertion, and he was right.

Williams Index

Using the method outlined in this post, I substituted Ashley Williams for both central defenders in each of the big 5 EPL teams. And as the graph above shows, he’s a net increase for all of them. Liverpool would hugely benefit from Ashley Williams, while the Manchester teams would get a mild boost over their current options. Chelsea was surprisingly high, Arsenal less so.

You can argue whether a 31 year old central defender is worth the money, but he’d be a significant enough upgrade for Liverpool in the short-term that it would be tough to argue against. Chelsea has some good, younger options with Kurt Zouma and (if they eventually sign him) John Stones, who can only improve over time, but Rio appears to be right when he said Williams is “probably the most underrated defender in the Premier League [over the] last couple of years”.

I’ve been posting a lot of graphs like these on Twitter lately, so follow me @Soccermetric

 

 

Squad Depth may be why Man City wins the EPL

Someone tweeted a Footplr Lineup link to Manchester City’s first and second teams the other day, and I had never really thought about how deep City really is this year. They are two deep in world class players at just about every position, with little drop-off at just about all of their outfield players.

photo (13)

So I ran this through my Transfer Evaluator and found something really scary: the evaluator actually has City’s second team as stronger than the first. I didn’t break down exactly why it likes this squad better, but I know it likes Navas over De Bruyne, and apparently likes Otamendi better with Demichelis than Kompany. It also likes Sagna a lot more than Zabaleta (and I don’t disagree), which I think explains most of the differences. Take a look and see the difference (click to zoom in):

city 2nd team

That’s about a five points gain from the second team to the first. Arsenal doesn’t seem to have the same depth, and this could be the difference, especially once injuries/suspensions start and in the crowded Christmas break.1

  1. I know Football Manager isn’t anywhere near real life, but I typically try to have basically two separate squads: a cup squad and a regular squad. I don’t want there to be any real drop-off between the two, and in Football Manager world you can do that sort of thing because world class players don’t mind being rotated out for half the season. Seems like City has actually pulled that sort of depth off, which is even tougher given the EPL’s roster limits.

The Ballad of Joey Barton

Even in the Championship, Joey Barton is still saying obnoxious things, so I thought I’d take a look to see what he would do if he was back in the EPL. Similar to last week’s “Zlindex”, I calculated the expected change in points if each EPL team signed Joey Barton. It’s not pretty, and explains why he’s not playing first division football anywhere.

Ballad of Joey Barton

Joey Barton would make all 20 Premier League teams worse. Most remarkable is how badly he would hurt Norwich City, a team that isn’t expected to earn that many points to begin with. The raw calculations predict he’d take them from 45 points down to 32 points, or down from 15th to 19th place (Barton would cost Villa 6 points, but they’re only starting at 36 so they’d be down to 30).

Surprisingly he wouldn’t hurt Arsenal that badly, and even more surprisingly after Jonjo Shelvey’s performance today against Manchester United he would only cost them about a point.  The average loss for an EPL team who signed Joey Barton would be 3.6 points, meaning he’d cost you a little more than one win a season.

So with the deadline fast approaching, West Ham can be glad they dodged that rumored bullet (but it’s still not too late to sign Zlatan).