Lets first talk about past occurrences of a double dip recession. The NBER has recognized 33 recessions since 1854 of which only 3 have been double dip. Out of the 3 only one occurred post-war which is the famous 1981 recession. The chances of a "double dip" recession has been historically low.The recession of 1981/82 was caused primarily by contractionary monetary policy to control high inflation which was 13.5% by 1980. Paul Volcker raised the fed funds rate up to 20% by 1981.
I would argue that the chances of a double deep recession are well within a 10%... What we may get instead is a an prolonged anemic recovery.