So it is with John McCain. Scarred, cranky and 72, he doesn't look much of a street fighter.
Yet he's gone six rounds with Barack Obama, and after his convention last week may yet still win.
From the outside, it seems inexplicable. Obama has near-cult status, the most powerful speaker for a generation.
As I saw for myself last week, McCain is perhaps the worst. Monotonous, clichéd and vague.
But his rare strength is that he knows his weakness. So he lets someone else dazzle.
McCain is perhaps the only politician in Washington who would have taken a bet on the unknown, untested Sarah Palin.
It is a massive gamble, what Americans call a 'Hail Mary pass'. But last week, it was "All Hail, Sarah".
Short of candles and incense, they could hardly have worshipped her more. Not just for who she is, but what she embodies. A Miss Alaska finalist who now governs the state and butchers moose in her basement.
I was sitting next to Eleanor Laing, a Tory MP, as I watched Palin speak. She kept saying to me: "It's like Thatcher." And it was. The idea that she who runs a household can run a government.
Millions who would never have voted for McCain are fired up about Palin. This, not the women's vote, is her point.
Thatcher once observed how men in Westminster suffer from defects they attribute to women: vanity and indecision.
McCain is guilty of neither. Only he would have picked Palin. Only he would have handed her what should have been his show.
As they tour American states, there's no doubt who the crowd's coming to see. McCain doesn't mind, as long as they show up.
There are plenty of other tricks in Team McCain's locker. He's lightning fast and his campaign turns on a sixpence.
Obama thinks: "What message will I put out today?" McCain takes the day's news story, and makes it work for him.
He turns Obama's force against him by casting his rival's positives as negatives. Eloquent? No, weasly smooth-talker. Popular? No, shallow Hollywood celebrity. Classy? No, uppity and aloof.
Meanwhile, McCain poses as the plucky underdog. In fact he's the one with seven houses. The one from the ruling Republican Party.
Obama is still stunned, unable to respond. He can't beat up a girl. McCain has outwitted him, not overpowered him.
His main problem isn't that he's too black. His problem is that he's too green, too inexperienced.
The case for Obama is made in single words: "change", "hope" etc. But ask him for a whole sentence, and he struggles.
A pastor recently did just that, and the Great Orator was lost for words.
My bet is that Obama will learn, regroup and win with a burst of energy towards the end - as he did against Hillary.
But he'll need all his wits and endurance to beat this all-American veteran who never says 'die'.
FRASER NELSON is also political editor of The Spectator.