You never win anything with kids. That nugget of received wisdom was proved to be absolute cobblers long ago over the course of a long English Premier League football season.
But what about a one-off, winner-takes-all finale to the biggest series in rugby? Do you opt for wise old heads, thrusting youth - or something in between?
It depends where you come from, apparently. Australian rugby, for example, usually worships youth.
They certainly did back in 2001, when a dreadlocked 20-year-old flanker was their star turn in a series triumph against the Lions.
The more times have changed, though, the more they seem to be trying to keep it the same.
The fact George Smith is back in the Wallabies starting line up 12 years after he was the player of the series against the Lions, and three years after he retired from the international game, suggests experience is now a prized commodity.
By contrast, on the other side of the park, their touring opposition have been happy to dispense with 133 Test caps and four Lions tours worth of experience for tomorrow's climax.
In Brian O'Driscoll's No 13 shirt instead is Jonathan Davies. At 25, the Welsh centre is not exactly a raw young buck, but he and Jamie Roberts, his fit-again midfield partner, have played less Tests between them than the Irishman.
So who is right: the ones who champion innocence or experience? One New Zealander will be proved correct tomorrow. And the other might not be welcome in his adopted homeland much longer.
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