Here is the risk. German bunds yield 2%. The germans have a budget surplus and a very reasonable debt load. So it may be assumed as a risk free return (relatively).
If greek bonds yield 62%, assume the chance of a default 100% tomorrow. So if the bonds were issued at a 6% rate, today they trade at slightly more than 10c. In reality, we need to calculate the average period of the bonds, which would be possibly 6 months. In which case, 20c is the average price.
After the default, assume a normal issued term yield of 6%. This chart states that in the case of a complete default today, the bondholders are looking at wiping out approx 80% of their value. If greek bonds are valued at 20c then the extra 1.2c equates to a more normal yield.
If the default is in a month, then add the interest paid to the post-default value. So if I hold the bonds, I get 5c for holding it for a month. Thus, a reduction to 20c leaves me a loss of 75c only.
In order for me to buy new bonds now at 6% and break even, then I need to recover 80c in terms of interest. Thats a holding period of 13 months.
This chart is telling us that the chance of a complete default within 13 months is 100%.
In practice, assume a 50% haircut. So in the case of a default, the greek govt will reduce the principal on bonds to half. In this case, I only need to recover 30c in case of new bonds. Thats a holding period of about 6 months.
If we assume a 75% haircut, thats an recovery of 5c in interest. Thats a 1 month holding period.
The markets are saying that there is a 100% possibility of a default (where 50-75% of the principal is wiped out) within a period of 1-6 months.
I need to go through this again to check the numbers - but its a simple model.
@Vitaliy_Kiselev The numbers simply state the timeline of the default. It should have been obvious a couple of years ago that Greece would default. Breaking down the probability simply indicates the timeline. While its not interesting to apply the numbers to Greece - these can be applied to Portugal or Ireland, or even Italy to check what the indicated timeline of default is.