The right shape? Rugby league, rugby union and boxing star Sonny Bill Williams.
The shape of a man's face can help predict his sporting acumen, according to a study on Wednesday that found Japanese baseball players whose faces were relatively broad rather than long were most likely to hit a home run.
University of London psychologists measured the facial width-to-height ratio, or fWHR, of 104 batters in Japan's professional Central League Pennant who played in the 2011 and 2012 seasons.
In both seasons, the players who scored the most home runs had the highest fWHR, said the study in the Royal Society journal Biology Letters.
Previous research has found a link between face ratio and competitiveness among politicians and financial success among corporate chiefs, but this work had focussed only on Caucasian subjects, not Asians.
The new data suggests the association "may be generalisable across cultures," according to the paper.
Why facial bulk appears to be so important in sporting success is unclear.
Wider jaws could be an indicator of testosterone, the male hormone that plays an important part in physical strength and aggressiveness.