Prime Minister's Questions is rarely a good indication of how a leader will perform at election time. William Hague frequently won his exchanges with Tony Blair but still suffered a landslide defeat in 2001. Gordon Brown's PMQs performances improved dramatically towards the end of his premiership but did little to boost his dismal poll ratings.
Yet, as all leaders testify, this single half-hour encounter every Wednesday remains a key determinant of party morale, and a single slip — "We saved the world" — is rarely forgiven. With this in mind, Ed Miliband can be more than satisfied with his performance today.
He began on a statesmanlike note, asking David Cameron for an update on his phone call with Barack Obama about the death of the aid worker Linda Norgrove. Then, after stressing his support for the coalition's reforms to sickness benefit (part of "responsible opposition"), he went on the offensive over the government's child benefit cuts, leaving Cameron, usually such an assured performer, more than a little rattled.
To the charge that he had punished middle-class families ("the deputy headteacher", "the police inspector"), the Prime Minister could only offer his stock reply that the £155bn deficit trumps all. To those families set to lose nearly £3,000, this will sound like a cold and technocratic answer.
Cameron made no sustained attempt to challenge the concept of universal benefits and, as a result, his words lacked intellectual clarity. But elsewhere there was what sounded like a cast-iron pledge to retain the winter fuel allowance in its present form. The much-anticipated war on the welfare state may not materialise after all.
But the defining moment came when Cameron challenged Miliband to explain his defence of middle-class benefits. The Labour leader's sharp response — "I may be new at this game but I think I should ask the questions and he should answer them" — revealed the luxury of opposition. Miliband will soon be forced to make tough choices of his own: on tax, strikes and the deficit. But with the largest cuts since the 1920s on their way, it is Cameron who will be on the defensive every Wednesday afternoon.
PS: One more positive conclusion from today: Ed Miliband can tell jokes. In reference to the shambolic Tory conference, he quipped: "I bet the PM wishes the BBC blackout had gone ahead." It was almost enough to make up for that clunky "train set" joke.