For example, I searched Bing for [wheat] and clicking through the pages of the search results, the numbers are not 1-10 results and then 11-20 results and so on. Instead it can be, 16-30, 31-45 and even more random. Sometimes they make no sense at all.
The WebmasterWorld member said he saw page 2 shows results 11-20 and then page 3 show 23-32 and page 4 show 35-44.
I am not sure if this is by design or if Bing is experiencing some sort of pagination bug?
Google has experienced several pagination bugs in the past, but typically only with specific queries and in rare cases.
Update: Bing sent us a statement:
We’re continually testing and experimenting on Bing in an effort to improve the user experience. We experimented with the number of answers for several months last year, and shipped the new format in June. In cases where there are answers (like a photo or video or news answer, we may provide a few more links to ensure there is right number of algo in addition to the answer blocks.
Forum discussion at WebmasterWorld.