In Google Webmaster Tools --> Seach Queries, you can see a list like this:
I am finding that the Avg. Position column o the above list is seriously out of sync with the Avg Position shown in the drill-down (which can be accessed by clicking on the key word)
Why do these differ?
Here is a lengthy explanation about the computation details (and the change in January) on the Google Webmaster Central Blog.
(I also noticed in one Webmaster account that most of the time I see correct averages but also some high values (like your "33" that sometimes more, sometimes less significantly changes on the drilldown), in exactly 7 out of the default 25 results.)
So as long as there is no better conclusion out of the above explanation I assume this is a bug ;-)
Not much is known about the true inner workings of Google, however logic would conclude they use batch calculated figures. This means that depending on the query, not the underlying data, the results may be showing figures at another point in time and therefore not matching.
A big improvement was the tiering of the batches involved in the Caffeine update, but the extent that Webmaster Tools reflects this is also unknown.
Google Web Master Tool will not tell the exact stats , I found lot of Missing stats in my case also . Dont depend seriously on these stats, some of the positions which it shows in webmaster tools never reflected in reality in my case.
