Weight: 113kgs (17st 9lbs)
Ireland caps: 28
Why he's so important? He has matured into a super Test match forward who can play both secondrow and flanker without any diminution in the influence that he brings to bear on a game. His ability to read the ebb and flow allows him to maximise his athletic qualities whether that's out near a touchline in general play or pilfering the ball at the breakdown.
Friend and foe alike acknowledge his remarkable capacity to pinch turnovers or force penalties. The consistent quality of his contribution has made him largely indispensable for the national team in recent times. He is Ireland’s version of Maro Itoje.
Trivia: He became the first new addition to the wall of names in the Guinness bar at the newly refurbished Cashel Palace hotel, joining a list of Hollywood luminaries Elizabeth Taylor, Rod Steiger, Richard Harris, Robert Mitchum, Peter O'Toole, John Huston, Angela Lansbury, Ronald Reagan and Daniel J Travanti of Hill Street Blues fame.
Weight: (115kgs) 18st 2lbs
England caps: 54
Why he's so important? He is a focal point for every team on which he plays whether that is an Under-20 World Junior Championship winning side, claiming a Champions Cup with Saracens or at Test level with the Lions and England. Quite apart from his athletic prowess it is his ability to think his way through the game and maximise his impact that is arguably more impressive.
He is a scourge at the breakdown, a nuisance out of touch while on the flip side he is the consummate team player in facilitating others. The similarities of his physical attributes and style of play with Tadhg Beirne is striking.
Trivia: He went to the secondary school St George's in Harpenden, which was also attended by England teammates Owen Farrell and George Ford. He represented England at Under-17 level in basketball while he also threw the Shot Putt for his country at schoolboy level, before finally settling on rugby.
His nickname is 'The Pearl' and in 2020 he launched a podcast called Pearl Conversations, where he talks to groundbreakers from across society.