Controversial underarm serve proves popular tactic at French Open

It has been seen as one of the more controversial tactics in tennis over the years, but it seems that the underarm serve is becoming a common feature in some matches at the French Open. The likes of Alexander Bublik, Sara Errani and Monica Niculescu have all hit underarm serves this tournament- admittedly to varying levels of success- though it is certainly a tactic become more common in recent weeks. Over the past few years one person to have regularly used the tactic is Nick Kyrgios. The Australian has been known to hit an underarm serve against those who sit very deep when returning, such as Rafael Nadal, and it is certainly becoming a potential tactic...