For the second season running, Carlos Alcaraz and Jannik Sinner shared all four Grand Slam titles between them in 2025.Three of the four Slam finals – the French Open, Wimbledon and the US Open – were contested by the top two in men's tennis, with the Australian Open, in which Sinner beat Alexander Zverev in the final, the sole exception.It is 10-11 that the great rivals meet in a fourth successive Slam decider in Melbourne this month, a feat last completed by Novak Djokovic and Rafael Nadal at the 2012 French Open, and the concern for those looking to oppose the top two is that there appears to be a genuine lack of emerging talent.Two-time defending champion Sinner is seeking to complete a hat-trick at Melbourne Park and the Italian looks less likely to slip-up than Alcaraz, who, at 22, will become the youngest man to complete the career Grand Slam should he win the singles title.However, the Spaniard has yet to go beyond the quarter-final stage on four previous trips down under and his decision to split with long-time coach Juan Carlos Ferrero, who had been alongside him for 15 years and for all six of his Grand Slam title triumphs, seems untimely and could lead to a lack of focus.