Novak Djokovic Will Outlast Juan Martin del Potro in Thriller

Novak Djokovic and Juan Martin del Potro will meet in a semifinals clash at the Barclay's ATP World Tour Finals on Sunday. They will meet for the ninth time in their careers while Andy Murray and Roger Federer make up the other part of the semifinals.

Here are two reasons Djokovic will outlast del Potro: 

Career record vs. del Potro

Djokovic is 6-2 all-time against del Potro since the Argentine turned professional in 2005. He has dominated him just like he has with most players on tour.

Right now, despite struggling in parts of the year, Djokovic is still the best player in tennis. He has earned the right to be called this after going 70-12 in 2012, according to ESPN's statistics. This coming after one of the greatest years of all time. 

Hard court

Djokovic is 4-1 all time against del Potro on a hard surface—Djokovic's favorite surface. His ability to dominate on the surface is documented and he has proven to be the best player on the surface over the past two years.

If this was another surface, del Potro would have more than a puncher's chance. But with this semifinal on the hard court, Djokovic has this victory in the bag because of his ability on the surface and past experiences against del Potro. 

From being successful on the first serve to hitting his spots on the court, no other player can do what he can do on a hard court. 

Prediction

Djokovic escapes a feisty del Potro while Andy Murray knocks off Roger Federer, setting up this year's best rivalry: Novak Djokovic vs. Andy Murray.