World Football Transfer News: 7 Ways to Better Evaluate Top Transfer Targets

As an American writing about football, I often receive comments from European readers that I place too much emphasis on statistics.

They argue that unlike American sports such as baseball and basketball where a player's performance can be evaluated by his ranking in several statistical categories, a footballer's worth cannot ultimately be determined by his statistical performance.  Rather, other immeasurable factors such as creativity and the ability to fulfill a particular tactical role determine a player's true value.

While I agree that even our best attempts to quantitatively evaluate a player's performance never presents a perfect representation of his actual contributions, statistics, when properly interpreted, can provide us with a more informed perspective and help us distinguish between similarly regarded players.

As we are now firmly engrossed in the 2011 summer transfer window, here are seven statistical categories which will help you more comprehensively evaluate your team's top transfer targets.

1. Goals

The single most important statistic in football, goals are the clearest indication of offensive proficiency. 

Naturally, we tend to assign the greatest importance to the players who score the most goals.  However, while we praise attacking juggernauts Cristiano Ronaldo and Lionel Messi for their goal-scoring prowess, we must also realize that the number of goals scored can also be used to measure the effectiveness of midfield and defensive players as well.

For instance, let's take the case of Arsenal center half Thomas Vermaelen. 

Injured most of this season, the Belgian International scored eight goals in 43 appearances for the Gunners during the 2009-2010 season. While his goal return was significantly lower than several of his teammates, his unusual ability to advance forward from defense and present a consistent threat in attack made him a major asset and a persistent nuisance to opposing teams.

While we cannot criticize non-strikers for failing to score, we can assign special importance to those players who manage to score regularly despite occupying deeper-lying positions.

2. Assists

Another obvious indicator of offensive success, assists are often overlooked when evaluating transfer prospects. For instance, most fans realize that Cristiano Ronaldo scored 54 goals this season, but far fewer football fans realize that his teammate Mesut Özil bagged an impressive 26 assists. Instead, fans and the media use other proxies for assists such as "creative" or "influential."

However, similar to goal return, we can use a player's number of assists as a more objective measure of his offensive influence.

Let's take the case of Everton left back Leighton Baines. Formerly linked with a move to Bayern Munich and now discussed as Arsenal transfer target, the England International is discussed with the likes of Manchester City left backs Gaël Clichy and Wayne Bridge.  However, his statistical performance suggests that he is significantly better than either of the Manchester City defenders.

In addition to scoring seven goals, Baines also contributed a very impressive 12 assists. When also considering the Everton man compiled these statistics while playing as a defender for a mid-table team without a dominant striker, we realize that Baines is quite simply the best wingback in EPL.

With the ability to move forward consistently and place pinpoint crosses onto his teammates heads, he should be one of the most coveted players in this summer's transfer window.

3. Second Assists

While strikers, forwards and wingers often compile the lion's share of both goals and assists, deeper-lying players often fail to receive statistical recognition for their influential performance.

For instance, let us take the case of the talismanic Barcelona duo Xavi Hernández and Andrés Iniesta.  Despite being regarded as two of the top players in the game, they only combined for 14 goals and 19 assists this season, far less than the 50 goals and 21 assists collected by their iconic teammate Lionel Messi.

So how can we better evaluate the midfield playmaker?

Using a metric which I borrowed from Ultimate Frisbee, the second assist is awarded to the player who assists the player who ultimately assists the goal scorer.

So, let's say that Xavi plays a brilliant 20-yard through ball to Lionel Messi. Messi collects and slides a pass across the face of goal to David Villa who taps in for an easy finish.

Currently, Villa would receive credit for the goal, and Messi would collect the assist.

However, by counting the second assist, we could credit Xavi for his excellent pass.

4. Points = Goals + Assists + Second Assists

In order to comprehensively measure "influence" or "creativity", we could add goals, assists and second assists and label the sum as points.

While we currently cannot perform this simple operation without the second assists statistics, I would be willing to bet the best offensive players in the world probably consistently tally over 30 points per season.

While defenders will obviously account for fewer points, we could use points to identify unusually influential backs such as Leighton Baines.

5. Number of Touches

Though this statistic would be quite monotonous to measure, the most influential players quite simply touch the ball more than their less talented counterparts.

To illustrate this point, let us compare the performances of two distinguished footballers: Manchester United and England center forward Wayne Rooney and Los Angeles Galaxy and United States attacker Landon Donovan.

Largely regarded as the third-best player in the world behind Barcelona's Lionel Messi and Real Madrid's Cristiano Ronaldo, Rooney has gained international acclaim for his constantly expanding portfolio of incredible goals.

However, his value extends well beyond his ability to score. When not receiving decent service or when his team is struggling to possess, Rooney drops deep into midfield where he can collect and play world-class passes to open up scoring opportunities for his teammates.

Similarly to Rooney, Donovan is a prolific playmaker who holds the United States Men's National Team (USMNT) record for most goals and assists. Nevertheless, despite his talismanic abilities, Donovan will often fail to touch the ball for long stretches of important games.

While certainly an excellent player, Donovan ultimately lacks the constant influence to be held in the same regard as Rooney.

6. Minutes Played

This statistic provides managers with two very important pieces of information.

Firstly, top players regularly feature for their sides. So, if a team acquires a player who has played 90 minutes in 35-40 games, the fans know that he is talented enough to crack the starting 11 and accustomed to handling his responsibilities.

If a player does not regularly feature, even if he is obviously talented, he may not be mature enough to adjust to playing for a bigger club.

Such appears to be the case with New York Redbulls striker Juan Agudelo. While the 18-year-old has impressed in limited appearances for both the Redbulls and United States Men's National Team, he has not yet proven himself as capable of consistently contributing as a starter. 

While he will likely develop into a great player, he will require another two to three seasons of development before he is ready to regularly feature for a European club.

Secondly, top players are only effective as long as they remain healthy. For instance, while Barclelona players and fans are apparently thrilled about the possibility of Arsenal Captain Cesc Fàbregas moving to the Nou Camp (big surprise), I am skeptical about the transfer. 

The Spanish International only featured in 22 of Arsenal's 38 EPL games this past season. With recurring niggling injuries constantly affecting his form, would he be healthy enough to establish himself as a regular in Barcelona's starting 11?

7. Plus/Minus Differential

Thus far we have discovered statistics which allow us to compare players directly to other players.  However, plus/minus differential is a unique statistic which allows us to measure a particular player's impact on his team's performance.

Borrowing this metric from basketball, plus/minus differential would be calculated by comparing the number of goal differential when a particular player features compared to the number of goal differential when the player does not feature.

So, let us say that Team A has a goal differential of plus-10 when Player X is on the field and a goal differential of minus-two when he is on the bench. In order to calculate plus/minus differential, we would subtract the team's goal differential without Player X (minus-two) from the goal differential with Player X (plus-10).

Our result of 12 would indicate that there is a 12-goal difference between the team's performance with Player X compared to their performance without Player X.

This metric is particularly useful for measuring primarily important defensive players who don't accumulate a great deal of goals, assists, or second assists.

Take the case of Real Madrid holding midfielder Lassana Diarra. Largely underappreciated by his own fans, Lass is often the cog that holds Manager Jose Mourinho's defensive juggernaut in place.

Often preventing opposing attackers from converting possession into legitimate scoring opportunities, I suspect that Real would have a much more favorable goal differential when he features as opposed to when he is forced to the bench.

Conclusion

As you surely realize from reading the previous slides, these statistics primarily measure the qualitative category of "influence".

You might respond by arguing that this approach is biased to reflect the performance of offensive players and does not adequately measure defensive effectiveness.

Ultimately, you would be right.

Despite my best attempts, I have not yet devised a method to quantitatively measure a player's defensive prowess.

Please comment with any ideas on how we could statistically measure players' defensive contributions or what you think of my proposed method of measuring "influence."