Identifying the difference between good and great is not easily done with the naked eye. When a player steps up to a new level, it is far easier to find the reason why on a stats sheet than piecing together his great play watching from the side of the court.

Milos Raonic is a perfect example.

Raonic has had a magnificent run through to the quarter-finals of the Australian Open this week. His fourth-round victory over San Wawrinka in five sets was particularly impressive.

So what exactly is driving Raonic’s deep run Down Under?

The best way to uncover his improvement is with an Infosys ATP Beyond the Numbers analysis.

Raonic made exactly the same amount of first serves (64 per cent) during the 2015 season as he has made in the first four rounds in Melbourne, but he is winning two per cent more (83 per cent to 81 per cent) in Melbourne this year.

You may think the hot weather conditions have something to do with that, but it’s actually been a very mild to cool Australian Open so far.

Raonic's performance on second serve is identical for the 2015 season and this year's Australian Open, winning 58 per cent of those points. It’s amazing how some things change, and some things stay exactly the same. Service games won is also identical, at 94 per cent - 67/71 in the run to the quarter-finals.

Raonic is widely admired for his prowess on the serving side of the equation, but it’s really his improved returning this tournament that is specifically helping him lift his game.

In the 2015 season, Raonic won 24 per cent returning first serves. In Melbourne, through four rounds, that has leaped up to 32 per cent. Someone has been working on their defensive returns.

The same improvement can be found returning second serves.

In 2015, Raonic won 44 per cent facing second serves. That’s simply too low. The average so far in Melbourne into the quarter-finals is 49 per cent. That’s exactly where Raonic now finds himself, and that’s very bad news for all of his opponents.

Imagine facing one of the best servers in the game, who also has a return game that is not a weakness. That’s the full package.

The improvement in returning also naturally leads to more break points being converted. In the 2015 season, Raonic was at 33 per cent. So far in Melbourne, he is 38 per cent.

The Canadian is showing massive improvement in return games won, moving the dial from 12 per cent in 2015 to 19 per cent in his first four Australian Open matches.

Raonic now plays Gael Monfils in the quarter-finals, for a shot at the winner of Andy Murray and David Ferrer.

Raonic has lost to Monfils twice, so this will be yet another excellent test of the Canadian’s improvement. Monfils must do all he can to win the opening point of Raonic’s service games, because if he doesn’t, the metrics won’t be kind to him.

From January 2015, Raonic has gone up 15/0 521 times in his service games. He has won 506 (97 per cent) of those games. If he gets to 30/0, which he has 363 times, he has won 357 (99 per cent) of them.

If things get close, as they normally do in the second week of Grand Slam championships, it’s interesting to see how many times a player can be down set point, and still win the set.

Since January 2015, Raonic has done it 29 times. Monfils has done it 32 times.

This is the first seed Monfils has had to play in the tournament and it's a great opportunity for both players to reach their first semi-final Down Under.

Read more insights at Infosys ATP Beyond The Numbers