Dissimilarity between Webmasters tool & SERP

[zeus]

In the Google webmasters tool of mine, I found some of my keywords avg position ranking 15-20. But when i search for those keywords in the google search i could not find them in the first 10 pages. Why is it so??

In the webmasters tool of yours under the International Targeting see that if you are targeting all countries or some particular country. If you are targeting all countries then it is showing the avg position counting for all countries.