Little can produce big influence in a rugby context. Will Genia is once again one of those characters. He could, in fact, be biggest threat to the All Blacks in Brisbane this week.
Israel Folau and Kurtley Beale, two much larger gifted athletes, are more obvious candidates to single out. Beale, in particular, has added another attacking dimension since returning from Wasps to the Wallabies and finding a home outside Bernard Foley in this year's Rugby Championship.
But to find the true orchestrator of the Wallabies' recent revival, look no further than Genia.
There was a time, pre Aaron Smith, when Genia was considered the world's premier halfback. He was lethal, fast, accurate. Fourie du Preez, South Africa's last exceptional No 9, was another standout during this period.
For whatever reason, whether it was being suffocated in the Reds' demise, injuries or taking on too much responsibility, Genia lost confidence and eventually moved to France for two seasons, only returning to Australia this year and signing with the Melbourne Rebels for 2018/19.
Jake Gordon at the Waratahs offers promise but no Australian halfback came close to filling Genia's void. In his time, it's always been him and daylight. Now the veteran is back pulling the strings at the highest level, it should not surprise this has coincided with a much more fluent Wallabies outfit.
At this point in his career, now 29, Genia is comfortable voicing his views. After a poor first half against the Pumas in Canberra, he got seriously stuck into his team-mates in the sheds.
The difference between good and great halfbacks is their composure and option-taking. This year, Genia is nailing these duties.
Think back to the success the Wallabies had against the All Blacks in Dunedin. Genia was at the heart of it.
The Wallabies came hard, fast and direct. They got in behind the All Blacks too easily and cut them open at other times. The Springboks adopted a similar approach in Cape Town but did not have the same finesse from halfback to convert pressure into points. Other than Handre Pollard's brilliant burst and offload, the Boks were too predictable.
Genia offers a major point of difference. Experience has only enhanced his vision.
From a backpedalling scrum in Dunedin, his eye for a gap evoked memories of his telling try and the defining moment of the Reds' victory over the Crusaders in 2011 Super Rugby final at Suncorp where he was man of the match. While he may not have the same speed, it was a reminder of the threat he still poses.
Genia's control from the base has impressed in 2017. In the Wallabies last match against the Pumas in Mendoza, he had the ball on a string. He set up Reece Hodge by spotting the Wallabies wing unmarked on the blindside. Hodge had another ruled out where Genia skipped multiple players to hit him on the chest with a bullet ball that put him in a huge hole.
Elsewhere Genia expertly picked his forward runners; those coming at pace and targeting weak shoulders. The All Blacks have shown vulnerability with their ruck defence this year, and will be weary of Genia's subtle variations in close.
Smith is back in a groove this year and, yet, from a statistical point of view in the Rugby Championship, Genia was at least his equal. The pair had one try each; Genia two more clean breaks and more metres with 65 (Smith made 31). Smith made more passes (140 to Genia's 129).
What makes Genia more compelling is he rarely, if ever, enjoys a dream ride behind a Wallabies pack that can battle to generate consistent quick, clean, front-foot ball.
So much of the Wallabies game now revolves around playing off nine. Expect the All Blacks to, therefore, do their homework on Genia.
The best way to negate his influence is to dominate the collisions. The more forward runners are knocked back with force, the less time and space Genia has to assess and select the right options.
Even then, this savvy Papua New Guinea-born puppeteer is sure to create challenges.