There are few if any certainties in sports, tennis included.  A player can have all of the talent in the world, but there is no guarantee that he will make the most of it.  He has to push himself, dedicate himself to his craft, and find a way to create and come up good in those defining moments that can make or break a career.  Bernard Tomic may well find himself facing one of those pivotal moments when he takes on Andy Murray on Monday with a berth in the quarterfinals hanging in the balance.

Tomic is tasked with a tall order to get the better of the second seed in this contest.  Murray is a former Wimbledon and US Open champion, so he is quite comfortable with playing these kinds of matches.  Murray is also very familiar with competing at this stage in Melbourne.  The Australian Open has regularly been one of his best majors, as evidenced by his four finalist appearances.  With Novak Djokovic and Roger Federer tucked up in the top half of the draw, and the way things have transpired in the bottom half, few would bet against the Scot making his way to a fifth final.

Not many will favor Tomic's chances of stopping Murray's march to a fifth final either, but many, Murray included, will not rule out the possibility.  Tomic has long been thought to possess the talent to be a top player.  He caught the attention of the tennis world when he reached the quarterfinals of Wimbledon in 2011, and he has twice been to the fourth round in Melbourne.  Unfortunately, Tomic, along with his father, has often proven to be his own worst enemy.  He became better known for his excessive partying and skirmishes with the law than what he was doing on the court.  In recent months, however, Tomic looks to be taking his tennis more seriously, and at 23, he still has time to turn around his career.

Tomic would undoubtedly love to take a leap in moving his career in the right direction, but it is going to be difficult to do that against Murray.  The two tend to play with similar styles, probing from the baseline by giving their opponent different looks and consistently keeping the ball in play thanks to their exceptional foot speed.  The issue for Tomic is that Murray is more effective with this cat-and-mouse approach, and lately, he has been willing to exhibit greater offense.  Tomic has been working towards being more aggressive with his serve and his groundstrokes in order to keep the points shorter, but again, it is difficult for him to execute his style to the same high degree as Murray.

The other issue for Tomic heading into Monday's match is that he does not have a whole lot of reason to believe he can pull off the upset.  Murray has been here so often that the pressure of the moment is unlikely to get to him the way it might Tomic.  Murray has also not only defeated Tomic in their three prior meetings, but also he has done so in routine straight sets on each of those occasions.  Furthermore, Murray seems to be playing with freedom out on the court, knowing that a loss this year will not be as painful as in years past, since he will then get to go home to the birth of his first child. 

The lone distraction for Murray may come in the form of his father-in-law, Nigel Sears, who alarmingly collapsed in the middle of his charge Ana Ivanovic's match against Madison Keys Saturday night.  All reports since then indicate that Sears is doing better, however, so it is likely that Murray will be ready to go physically and mentally when he takes to the court against Tomic, which means the young Australian is going to have put his nose to the grindstone and prove to Murray, the fans, and himself, that he is ready to fight and take it to the Scot in an all-out effort to reach the last eight.

Even if he throws everything including the kitchen sink at Murray, it is hard to see Tomic getting through, short of Murray having to pull out for personal reasons.  But there is still a glimmer of hope, and at the very least, making it a competitive affair should help his career down the road.  So, with any luck, this will be an entertaining encounter worthy of the fourth round, but the Scot should advance.

The Australian Open is now known as the “Happy Slam,” and Victoria Azarenka is surely happy with how things have transpired thus far in Melbourne.  She had the good fortune of landing in the opposite half of the draw from Serena Williams and Maria Sharapova, and the slew of upsets that have ravaged the field have left her in a very favorable position to at least reach the final.  However, Azarenka will be fully focused on her upcoming encounter with Barbora Strycova. 

Strycova is hardly a household name.  Until now, her sole trip to the second week of a major in the singles competition came two years ago at Wimbledon, where she reached the quarterfinals.  She is presently ranked No. 48 but has been as high as No. 20.   The Czech is perhaps better known for her doubles play, where she has logged quarterfinal and semifinal finishes at the majors and attained a career-high ranking of No. 14. 

While Strycova has put together a respectable career, those are hardly credentials that are apt to intimidate Azarenka.  The Belorussian is a former No. 1 with two major singles titles under her belt – and they both came in Melbourne.  Foot and leg injuries have seen her struggle over the course of the last 18 to 24 months, but numerous people have believed it was only a matter of time before she regained her top form and again challenged the best in the game for the premier titles in the sport.  The 2016 season is not yet a month old, but it is increasingly looking like that time may be now.

There is certainly every reason to believe that Azarenka is going to continue her fine run by defeating her Czech opponent and advancing to the quarterfinals.  She is more solid from the baseline off both wings and makes more headway with her serve.  And while the former No. 1 may not be known for her movement, she is better than Strycova in that area as well.  Azarenka has also made noticeable strides with her net play and has become accomplished enough in the forecourt that it makes any advantage Strycova might have enjoyed as a doubles player in that department practically irrelevant. Further complicating matters for the Czech is the fact that Azarenka is one of the best returners in the game.  She has the ability to get on top of her opponent at best and neutralize the rally at worst with that one single shot, so Strycova is going to need to have an exceptional serving day if she is to stand a prayer in Monday's match.

Of course, in order to stand a prayer, Strycova herself must first believe that she does.  With her upset of Garbiñe Muguruza in the last round and the numerous upsets to have already plagued the women's draw, the Czech might find something positive to fuel some belief that she can get the better of Azarenka.  She is going to have to dig deep, though.  Not only does Azarenka have far more experience than her playing these types of matches, she is a perfect 4-0 against Strycova.  To add insult to injury, all four of those victories have come in straight sets, and the last two occurred here in Melbourne. 

Strycova will have to whip up something special if she is to flip the script on Azarenka by garnering the victory on Monday, and with all that has happened through the first week of the tournament, that is not out of the realm of possibility.  But it is not likely.  Azarenka is hardly playing like someone who expects to lose any time soon.  It should be business as usual as she takes one more step towards trying to claim her third Australian Open crown and return to the pinnacle of tennis.