On the ATP World Tour, it’s no longer the race for number one; the name of the game is now four. Who will finish the season ranked 4th in the world? It’s highly doubtful that the current world number four - Rafael Nadal - will be able to solidify his precarious position given the two tenacious players nipping at his heels.

Japan’s Kei Nishikori and Canada’s Milos Raonic are a mere 65 and 180 points respectively, behind the Spaniard. Stan Wawrinka, the newly crowned US Open champion, just added an additional 150 ranking points for reaching the final in St. Petersburg losing in three tight sets to the young German, Alexander Zverev.

The Swiss number two with 6,260  points, is firmly entrenched in the number three spot given his sizable lead over Nadal. This season marked the first time since 2004 that the Spaniard failed to make the quarterfinals at a grand slam event.

The 14-time Grand Slam champion lost to the talented young Frenchman, Lucas Pouille in the third round of the US Open. His position and dominance within the top four are undeniably tenuous given his recent results and wrist injury not to mention the significant strides made this season by Raonic and Nishikori.

The highly coveted number four spot is crucial because it determines the semifinal match-ups at the four slams. Nadal is in serious danger of losing his seat at the table as the indoor hardcourt season commences. Not his favorite surface by a long shot, the Spaniard’s record on carpet is a dismal 2-6 and luckily for him, has not been used on tour since 2009.

Of his astounding 69 career titles, only two have come indoors despite a respectable 68 percent win/loss record though it pales in comparison to those of Federer (81%), Djokovic (78%) and Murray (77%).

Incredibly, Nishikori and Raonic boast almost identical indoor hardcourt records. Both posted 55 wins with Nishikori having one less loss at 20 while both have won 5 titles. Perhaps another harbinger of things to come, both attained a career high ranking of 4 in the world in the spring of 2015. Nishikori, currently ranked five in the world, is just 115 ranking points ahead of Raonic; the race to number four –, not just the ATP World Tour Finals is on!

2016 was a pivotal season for both players. Raonic, at twenty-five years of age, made his first slam final at Wimbledon while Nishikori at 27 years of age made his second semifinal at the US Open having lost the final in 2014 to Marin Cilic.

After a disappointing second round loss to Ryan Harrison at the US Open earlier this month, the Canadian is undoubtedly motivated to perform well the remainder of the season and close the gap with Nishikori and Nadal. 

Unfortunately, both have been plagued with chronic injuries and this may be their Achilles heel; will their ability to permeate and dominate the game’s elite be undermined by their physical fragility?

The road to London and the ATP World Tour Finals may be bumpy for those players still striving to make the final eight but for Japan and Canada’s number one players, admission into the inner sanctum of the world’s top four would be the coup of the season.