The Wimbledon men's singles semi-final matches, one featuring Novak Djokovic and the other Andy Murray, have one thing in common—they are both classic cases of David vs. Goliath. Currently, Djokovic is the World No. 1 player. A semi-final match featuring such a player should have someone ranked fifth or above as the opponent. But with Roger Federer and Rafael Nadal biting the dust in the initial rounds, the task of taking down Djokovic falls upon Juan Martin del Potro, who is ranked World No 8. But, in the eight times the two have met, Djokovic has emerged victorious seven times. The second semi-final match has Andy Murray, who is the next best player after Djokovic on the basis of rankings. He too deserves to be up against a top 5 player. Forget top 10, his opponent is not even in the top 10. Murray needs to beat World No 22, Jerzy Janowicz, for a place in the final. Murray and Jerzy have met only twice before with the latter winning the last match between the two. 
Nevertheless, the semi-finals promise a cracker of a contest. Here's a look at the four semi-finalists.
Novak Djokovic: Djokovic is currently the best tennis player around and occupies the top spot in the ATP rankings. He has earned it through his consistent dominance at the courts over the last year. It will take more than a flash in the pan to take him down. The Serbian has won four of the last six Grand Slam titles, losing only on the clay courts of Roland Garros. Winning 35 per cent of his games in that situation in 2012, Djokovic seems to be at his best when returning the serve. When facing a second serve, Novak wins a world-best 57 per cent of points. The only weak spot is his serve. He hits only 63 per cent of his first serve and does not have great success even when the ball is in play. If del Potro is to take him down, he must take advantage of Djokovic's weak points.
Juan Martin del Potro: Juan Martin del Potro, even though a top 10 player, looks miniscule and amateurish when compared to Djokovic. This doesn’t mean we can sideline him. He is, after all, a top 10 player. While Djokovic’s weakness is his serves, Juan’s powerful serves is one of his strengths. His height gives him the advantage to attack the ball. Though clay courts are his favourite, he is good on all surfaces. Juan’s fitness and endurance (or the lack of it) have always been in question and his recent injury, which almost made him quit the tournament, has made matters worse. Del Porto is one of the more predictable of players, with a blatant lack of variation in his tactics.
Andy Murray: Andy Murray has on his shoulders all the hopes and dreams of the home crowd. It has been 77 years since a Brit won a Wimbledon crown. Considered one of the all-time great returners in tennis history, his length and dexterity gives him the ability to return shots that others cannot reach. Besides, add his ability to vary height, direction and pace on his ground strokes, and he becomes a lethal opponent. Despite his lanky stature, Murray possesses footwork worthy of his ranking. But Murray has a kryptonite — himself. His volatile mentality has led to his downfall countless times.
Jerzy Janowicz: Jerzy Janowicz’s current performance is his best ever. This means when he walks into the court for his semi-final match against Murray, he is neck-deep in unfamiliar waters. With Andy Murray up against him, the unfamiliar water he is neck-deep in is also shark-infested — he needs to proceed with caution as death is one wrong move ahead. If he can overcome his lack of experience and keep a check on the unforced errors (characteristic of his high risk style of play), he may have a chance at victory. For a big, tall man, he has good movement on the court, and with a commendable variety of shots and a solid backhand, Jerzy can manage to bring Murray down on his knees.