While watching the Ireland v Scotland Pool game last Sunday, it occurred to me that the Captain for both teams played in the same position in the team (Hooker or Number 2 - Rory Best for Ireland and Stuart McInally for Scotland). It made me wonder if this was a more common occurrence as I could recall some international captains in the past who also played in that position (Dylan Hartley of England and Sean Fitzpatrick of New Zealand were two that sprung to mind).
While admittedly a crude sample to examine, I collected data from the squads of the teams at the Rugby World Cup currently taking place (looking at club teams and/or teams over time would increase the sample size and perhaps give more insights). At least it is contemporary. The following Wikipedia page lists the squad members of each team and indicates the captain of the squad. In addition, information on their position, age and number of caps is also given. Of the 20 Captains at the Rugby World Cup, 10 are positioned in the Back Row (Numbers 6, 7 and 8), 3 at Hooker (Number 2), 3 at Centre (Numbers 12 and 13) and 1 each at Lock (Numbers 4 and 5), Fly Half (Number 10), Wing (Numbers 11 and 14) and Full Back (Number 15)
One should be careful with these numbers however as the back row position covers three personnel while the centre covers two and the hooker just one. To adjust for this, we calculate a ratio of the number of captains per players in that position in the squad listed at the Rugby World Cup. The table below presents the figures and shows that even when adjusting for the number of players, the Back row is still the most popular position for a captain in the current Rugby World Cup.