Both men have their fanboys and each were level on five Ballon d'Or each until Messi went clear last year and won his sixth.
Whilst us mere mortals struggle to separate them a supercomputer has done the work for us.
Sporza report that professors at KU Leuven university and data experts at SciSports have come up with a formula to decide who is the best player. Professor Jesse Davis explained how their system works, saying, "The value of a soccer player is often determined by goals and assists. A goal is a rare event, however, because an average of 1,600 actions are estimated to occur in a match.
"Our model looks at each action - shots, passes, dribbles, tackles - and calculates its value."
Using data from the two players from the beginning of the 2013/14 season until Ronaldo left La Liga to join Juventus at the end of the 2017/18 season the computer decided the Barca man was the better player.
Messi ended with Valuing Actions by Estimating Probabilities, or VAEP, score of 1.21 per game with Ronaldo scoring just 0.61 per game.
Tom Decroos, a PhD student who was involved in the research, explained, "In the first seasons, Messi and Ronaldo's scores are very close to each other.
"From the 2015/16 season, Messi has stepped away from his eternal rival.
"We see a trade-off with most football players: either they make a lot of actions with a less high value - that's the case with Paul Pogba, for example.
"Or you have players who are less likely to hit the ball, but who have a big impact. That is typical of strikers like Harry Kane, Mohamed Salah and Ronaldo.
"Messi is exceptional in this area: the Argentinian has a very high number of actions and they also have a high value."
Interestingly Ronaldo's score for Real, during the same period he was compared with Messi, and Eden Hazard's score for Chelsea in that time are very similar.
The Belgian, who has since signed for Los Blancos, actually had a higher score of 0.64 and Lotte Bransen of SciSports explained why the nature of how they got their points means Hazard is a good replacement but not an exact one, "Ronaldo is a classic scorer. His value is mainly determined by his good shots. Hazard is more involved in the game. His value is more spread over passes, dribbles and shots."
So there you have it, Lionel Messi is the best player in the world. You can't argue with a computer, because you look pretty silly if you try.