Link Statistic Discrepancy (or my misunderstanding)?

Understanding tools which give bank link data

[Philiboy]

Hi,

I use a number of web-based tools to obtain backlink statistics including the well known marketleap one. Can someone explain the following discrepancy? The marketleap report shows that a site has X backlinks on Yahoo!/Fast/Altavista. When you click on X which will be a link to the actual search engine listings, at first the X seems to be confirmed (the listing states something like "1 - 20 of about X for ...."). However, when you click through to view all the search results, it invariably only shows Y results where Y is far far less than X. Should I assume that X is just a wild guess and I should always use Y as the reliable data?

[Receptional]

I don't know about wild guess, but the general feeling is that yahoo's data on this is the best at the moment imho.

[Philiboy]

Thanks Receptional, but should I be using X (the value reported by marketleap which is the same as the "1 - 20 of about X for link:....") or Y (the number of results actually listed when you click through to the last result)?

[wmuser]

Probably thats because they arent submiting requests in real time but obtaining cached data from their database