After losing the Player of the Year award (Ballon d’Or) to Lionel Messi for four consecutive years Cristiano Ronaldo won the accolade in 2013. This and the great start Ronaldo has made in the new season have livened up an old debate as to whether he is a better player than Messi.
The discussion has focused on a particular set of statistics, namely, goals. To the extent that the data can help us to hazard an educated guess about player performance, Messi is the better of the two at club and international levels.
However if goals are used as the criteria to compare players it is not sufficient to look only at the number of goals scored. You also have to break down the conversion rate into such things as whether the shots are from inside or outside the area, the goal expectation i.e. whether an average player would score given the chance presented and the quality of the opponents.
The findings of a recent mathematical study were published in the Washington Post which showed that in 2009 to 2013 Messi’s average chance quality (i.e. quality of chances created) was higher than Ronaldo’s. Ronaldo had more shots but were mostly from long distance and he only scored 30 goals from 587 such shots whereas Messi scored 28 goals from his 287 long distance shots. Messi was more efficient because a higher percentage of his shots were converted i.e. 9.75 % to 5.11%.
The study found that Messi is better at getting into goal-scoring positions since he had 29 danger zone shots (from inside the area) to Ronaldo’s 20.
Messi is also a better finisher. In the period 2009/10 through 2013/14 Messi averaged 40% more goals than expected goals compared to Ronaldo’s 20% (see WASHINGTON POST – Despite great season, Cristiano Ronaldo is not better than Lionel Messi; by Michael Caley, November 7, 2014).
Last season Ronaldo broke the norm and outscored Messi. This propelled him to win the Ballon d’Or in 2013. But this has to be looked at in light of the fact that Messi missed a part of the year through injury and when he resumed playing he almost caught up with Ronaldo’s tally of 31 by scoring 28 by the end of the 2013/14 season.
Also, in the current season Ronaldo has made a great start by scoring 12 non-penalty goals to Messi’s 7. A plausible explanation for this is not that Ronaldo is now a better player but it is attributed to the changing roles of both players at their respective clubs.