Marin Cilic’s victory at the U. S. Open came out of absolutely nowhere.

Prior to this year’s tournament, Cilic had only seen the semifinal stage of a Grand Slam once before. The cool, calm and collected 25-year-old Croatian had been a mainstay near the top of the men’s game for quite some time but was never a favorite to win a major until he broke through in New York.

In the wake of Cilic’s victory in New York, we can extract a vital lesson regarding consistency by contrasting how Cilic approached his tennis in New York and how Frenchman Jo-Wilfried Tsonga has approached his tennis in the latter stages of majors over the years.

Tsonga has been challenging the elites of the game for years with very little to show for it. In his defense, he has been dealt an extremely unfavorable hand in having to overcome the stranglehold that the Big Four of Novak Djokovic, Rafael Nadal, Roger Federer, and Andy Murray has established over the ATP.

While it would be misguided to argue that Tsonga hasn’t improved areas of his game over the years, one would be hard-pressed to say that he has made the essential strategic adjustments to consistently deal with the Big Four. Maybe he thought about making these adjustments, and maybe he practiced varying his tactics, but none of it came into fruition on the match court.

To this day, Tsonga’s Achilles heel is that he is still far too impatient from the baseline and beats himself much more than he should. He has been unwilling to flip the script and look to add more consistency to his own game. One might wonder why Tsonga would look to deviate from his natural style of play. The answer is simple:  because it wasn’t working against the Big Four at majors and, more importantly, because he still has zero major titles to his name.

His fourth-round match at the U. S. Open against Andy Murray, a player he had beaten a few weeks before in Toronto, was the ultimate substantiation of years of failed tactics. Tsonga committed 43 unforced errors in that match alone, compared to Murray’s 18, thus meaning that Tsonga essentially gave away an entire set to one of the greatest defensive players this sport has ever seen. He’s hyper-aggressive to the point where some of the shots he attempts can only be described as being pulled out of thin air. They simply are not there to be hit.

Tsonga may end up turning a new leaf and winning majors, but until he reins in his aggression, it’s tough to see happening.

By contrast, Marin Cilic has benefited greatly from incorporating the insights of his coach, Goran Ivanisevic. Ivanisevic has lowered Cilic’s ball toss, creating a more continuous, rhythmic motion and adding significant power. Evidenced by his performances in the final three rounds, Cilic was also told by Ivanisevic to embrace the baseline and use his weapons. This is something Tsonga has been doing for years, but the difference between Tsonga and Cilic is that Cilic was able to control his baseline game and infuse it with a highly lethal element of consistency. In Cilic’s final three matches at the U. S. Open, he hit 41 more winners than unforced errors. We were all amazed with Cilic’s free-flowing power, which churned out winner after winner, but what was even more special was his undeterred consistency. Tsonga will come up with a lot of these same flashy winners but rarely will be able to maintain the same consistency.

At the end of the day, even at the professional level, most points are ended on errors and by the mistakes of opponents. As a result, Cilic’s brilliance at the US Open was not only visible in his capacity to bludgeon his opponents off the court but also in his ability to make his opponents come up with an equal level of greatness to win, which they ultimately could not do.