1. Whether David Cameron and Gordon Brown look down the camera.
2. How many times any of them say "I agree with..."
3. Gordon Brown's planned attempts at humour.
4. Nick Clegg's joke about going from Churchill to Hitler in a week.
5. Any sign of hubris from Nick Clegg.
6. How many times Nick Clegg mentions to two old parties.
7. An appeal to Nick Clegg for UKIP votes over his In/OUT referendum
8. Whether Adam Boulton imposes himself more on the debate than Alastair Stewart did.
9. How David Cameron lays into Nick Clegg without appearing to.
10. If Nick Clegg can escape the dog's breakfast of his policy on replacing Trident.
11. How many minutes it will be before Nick Clegg mentions LibDem position on Iraq.
12. How many times Nick Clegg says "we got it right on Iraq".
I'll be on 5 Live at 7.30pm and then after the debate with Tony Livesey doing the pre and post debate commentary.