There were four head-to-head battles, adjudicated by the capacity crowd waving their red and blue cards in the ideas-based collisseum of the Purcell Room.
ResPublica victory over Progress over whether Red Toryism had anything to offer: Blue win for Phillip Blond and Will Hutton, over Jessica Asato and Lance Price.
Fabian victory over Reform in defending the universal welfare state, against the argument for cutting middle-class entitlements as unaffordable. Red win for Sunder Katwala and my splendid debating partner Mary Riddell, over Dale Bassett and Dr Patrick Nolan.
An IPPR victory over Policy Exchange over the issue of governing markets, and whether successful markets needed more state intervention or less.
Red win for Carey Oppenheim and Neil Jameson of London Citizens over Andrew Lilico and Professor Phillip Booth.
RSA victory over Demos over whether it is social networks or character which matter most for opportunity, mobility and life chances? Red win for Matthew Taylor and Jonathan Rowson over Richard Reeves in this battle of the non-aligned centrists.
(That fixture led Rory Bremner to muse aloud as to who might be assigned the red or blue cards: I think my heckle from the floor may have been decisive in putting Demos in the blue camp, perhaps fairly since Reeves' "character" argument was an attempt to take the liberal centre on to territory he argued was mostly seen as the terrain of the right, and Taylor's argument was more social democratic in stressing the social production of character).
There was then a panel discussion between the ResPublica, Fabian, IPPR and RSA winners, though time limits meant the idea of any additional audience knockout vote was dropped.
(One format issue, which led to rather less 'battle of the band' cut and thrust than there might have been was that the first think-tanker and their expert champion spoke for two minutes each, before both their opponent and their second replied. This was particularly tough for Progress. The on stage coin toss meant they had to challenge Red Toryism before it had been advocated, allowing Will Hutton to challenge them for making a primarily negative argument. Jessica Asato did get to respond that the Labour government was putting into place mutualism in the banking sector and with the Ownership Commission, under Will Hutton's chairmanship. So was Hutton's argument that the Tories were more likely to regulate the City than Labour - "despite George Osborne" - plausible?)
So it was a good night for the political left, bouncing back strongly after falling a goal behind, thanks to star striker Phillip Blond relying on an assist from loan signing Will Hutton. The question could well be asked as to hiw far that was because this was a home fixture, with the relatively affluent, liberal audience at the South Bank Centre likely to lean leftwards on social issues at least, and how far it was a response to the ideas and arguments on the night.
There were neutral observers who felt there was an element of both.
For this was also an audience demographic which should have been somewhat open to Cameronism a hearing, and which was open to a softer and more eclectic compassionate or progressive conservatism. What was striking was how much those ideas or that tone were largely missing in action in the arguments made broadly from the right-of-centre on the night.
Indeed, the substance of Cameronism was challenged by thinkers usually sympathetic to what it is attempting. Matthew Taylor was laudably non-partisan in promoting the RSA's evidence. But he did challenge the David Cameron "warmth, not the wealth" claim in a Demos speech that good parenting meant income or poverty didn't affect life chances as (purely on the evidence) you understand, "nonsense". Yet Reeves countered that David Cameron talking nonsense about the subject didn't invaldidate the importance of the issue or Demos' research into it. Not perhaps the most full-throated defence of his keynote speaker, though it was a riposte in tune with that the academics concerned have said about the misinterpretation of their research.
Progress' argument had been that the ideas and instincts of Red Toryism , which were often laudable on the challenge to marketisation in particular, were often laudable, but were rarely reflective of any substantial body of Tory opinion. That contention lost the first knockout bout, yet it was one which looked rather more plausible as the evening went on.
Reform had put up an honest and intelligent argument for welfare retrenchment as a route to reducing public spending: arguing that the size of the pie was largely fixed, and if there was less to go around it was important to spend it where it really mattered, on the poorest. (My counter-argument, based on the Fabian Solidarity Society book, was that in a political democracy the size of the pie is never fixed, and there would also be longer-term fiscal pressures created by a lack of provision leading to a reluctance to pay taxes).
Yet Policy Exchange, represented by Andrew Lillico and Phillip Booth, put up a defence of markets which was eye-wateringly unnuanced. I spoke to right-leaning as well as left-of-centre voices which found the deeply unrepentant case for more market and much less state unpersuasive: that there was nothing to learn from the crisis except that states had over-regulated ineffectively, and that it was a mistake to then step in and save the banks.
This seemed boilerplate stuff, which could have been reheated from an Institute of Directors bash in 1985. Yet, surely in a world where the Bush administration had decisively rejected that advice, this was fantasy politics in refusing to engage with the real world of policy decisions.
During the event, Will Hutton had spoken of a "battle Royale within the right", arguing that the fate of liberal Toryism ought to be important to non-Tories, particularly as the forces ranged against liberal conservatism inside the party were strong.
Carey Oppenheim, co-director of ippr, said afterwards to Next Left that:
People seemed very responsive to opening up politics: to giving more power to citizens to make choices.
But the emerging agenda around Red Toryism felt very out of synch with the centre of gravity of the arguments from Reform and especially Policy Exchange, and most of the current thinking within the right.
Phillip Blond, acknowledged that the event had revealed this, though remained characteristically irrepressible about his ability to win through.
Tonight showed that transformative conservatism has fewer advocates than it needs but we have an evident and real purchase on the future.
The final session involved ResPublica, the Fabians, the RSA and IPPR did demonstrate some areas - innovation in public services; devolution of political power - of significant convergence between several of the thinkers of left and right.
Overall, the event more often demonstrated that the instincts, intuitions and priorities between thinkers of the left and right, especially on major issues of the scope and scale of public intervention and redistribution remain rather distinct.
As well as endorsing a more pluralist and participatory politics, most centre-left participants were focused on distributional fairness in markets and society - Richard Reeves on the need to make the challenge to the idea that "birth is destiny" central to any vision of a good society from any party; Carey Oppenheim focusing on the change in top pay and how to regulate markets effectively; while I wanted to put choices about the tax burden as well as spending priorities were on the public agenda.
Most of the broadly right-leaning participants focused sharply on much deeper cuts in public spending than either the Conservatives or Labour currently envisage. Phillip Blond, like Matthew Taylor from the centre, was among those to look for where this could open up new space for innovation. But most of the right's advocacy suggested that the cuts focus is more likely to crowd out any fledgling progressivism as to open up new space for it.
Host Rory Bremner ensured the occasion was enlivened by impressions of Broon and Blair, David Cameron and Vince Cable.
Perhaps we could have done, along with the centrists of Demos and the RSA, with the LibDems of CentreForum in the think-tank clash.
But perhaps Bremner may be worried about having an identifiable Nick Clegg ready by the time we all hit the hustings:
"I met Nick Clegg, he said can you do me yet, and I said No, can you?".