Andy Roddick, widely regarded as one of the greatest servers in tennis history, has offered a fascinating breakdown of why Alex Eala's comparatively slow serve is causing serious problems for opponents on the WTA Tour.

Eala's rise into the top 20 has ignited debate about whether her serve can hold up at Grand Slam level. Her first delivery can reach around 100mph, but her second often sits between 60 and 75mph, leaving her ranked outside the top 50 for aces and both first and second serve winning percentages. Rennae Stubbs, who coaches Serena Williams, initially argued the 21-year-old Filipina could not win a major with that kind of serve, though she softened that stance following Eala's Washington Open title. Former British No. 1 Greg Rusedski has also suggested there is room for improvement, but believes Eala can develop the shot over time.

Roddick, speaking on his show "Served," cut straight to the heart of the matter. He explained that a slow serve on its own is not a weapon unless the server can punish any weak return, and Eala absolutely can. Her ball-striking ability is elite enough that opponents must genuinely "square up" every return, or face an immediate, aggressive follow-up from the left-hander.

Roddick drew on personal experience, recalling how Mardy Fish used to frustrate him with a modest 81mph kick serve precisely because Roddick struggled to generate enough pace off his return to take control of the rally. The same dynamic is playing out against Eala, who was able to unsettle even Iga Swiatek with her slower delivery at Wimbledon.

TennisDraw users tracking Eala's bracket progress will want to factor in this underrated serving strategy when making their predictions.