It is constant and it is confounding. It is history, art and arithmetic. In 2011/12, Lionel Messi's 50 goals in the La Liga were more than 13 clubs could muster all season.
In precisely the same period, Cristiano Ronaldo became the first player to score against every La Liga club in a single season.
Something beyond mere one-upmanship is still happening here. More like a private conversation through public goals. Both men want to win trophies, yet score as if replying to each other.
Both are fathers playing with the abandon of boys, who must invade each other's dreams in the form of nightmares. Either way, it is a relief in a world of Fifa politicking and a gift in a time of mouthing-off managers.
It is excellence so endless that we're in immediate danger of becoming blase about their beauty. Goals? Again? Yawn. In his home, Ronaldo must have a vault reserved only for Match Balls. Tradition demands they are given to the scorer of a hat-trick. He has over 20 of them in La Liga.
On an erratic planet, two things we can be almost sure of most weeks: Kim Kardashian's bottom will be discussed on the Net and
"RonaldoMessi" will find the net. The Portuguese has 197 goals in La Liga, the Argentinian has 253. The former, at 29, is two years older according to birth certificates; the latter, who started in the La Liga in 2004, is five years older in the League.
It is a duel that has purists - as they do in gymnastics - giving them imaginary marks for artistic expression for every goal they score.
Others prefer real numbers and fittingly even their figures have followers. One Twitter handle, messi10stats has 299,000 followers, while cristianostats has 262,000. Among the more prosaic facts you might find is that Messi has 71 Champions League goals. Ronaldo has 70. This is stalking in its only permissible avatar.
These men are scholars in the art of striking. Ronaldo sees opportunity before it is fully presented, Messi sees space before it completely opens. Ronaldo has scored a goal in every possible minute of a game, Messi seems to have scored every possible type of goal.
Their goals are classified by statisticians into "inside the box", "free-kicks" and "penalties". There is also "out of the box", a reference to a prescribed area and also their imaginative thinking.
Ronaldo ends goals with a run, a leap, a twist, landing with arms slightly spread, as if asking: did you see what I did? Messi, more than a scorer, tends to wheel away, leaving us to ask: did we just see what we did?
MessivsRonaldo will upset some people because they will say it should be RonaldovsMessi. Little is agreed upon here. Except that one uses more gel and sells more shirts. Forbes.com had a 2012 story titled, "Is Cristiano Ronaldo The World's Most Marketable Athlete?"
Certainly, if you add together the Twitter followers of Roger Federer, Tiger Woods, Lewis Hamilton, LeBron James and Sachin Tendulkar, they are fewer than Ronaldo's 31.4 million.
Messi is confronted by headines rather different: more like "Is He The World's Greatest Ever Footballer?" It's not the size of the numbers, he might argue - he has almost 75 million Facebook likes to Ronaldo's almost 103 million - but their heft. By one count, he has 22 team trophies to his rival's 16; he has been the world's best footballer four times and Ronaldo twice.
Either way you lean, together they have made us reconsider the once rigid idea that World Cup victory is necessary to this debate.
MessivsRonaldo is proof that the god of this game has some creativity of his own for they are cut from stylishly contrasting cloth. One is 185cm, the son of a gardener and a cook, and moves like a light-footed bull; the other is 169cm, child of a steelworker and a cleaner, and moves like an electric current.
One hangs in the air longer than gravity ought to permit, the other seems to glide across the earth without touching it. Wings of a different type.
We can view them as antagonists but in truth they together produce weekly anthems to football. They play almost in praise of the game, a dancing devotion that has resulted not just in goals but something more profound: they have helped football evolve.
In sport, it is human nature for watchers to rate, compare and place rivals in talented order. Yet, in a more critical planet, to elevate one athlete often requires a diminishing of the other.
As if we cannot admit that both things are possible at once: one man may give more pleasure yet to watch the other remains a privilege.
This article was first published on November 25, 2014. Get a copy of The Straits Times or go to straitstimes.com for more stories.