Matthew McGiffen looks at a common problem with statistics:
The Ascending Key Problem relates to the most recently inserted data in your table which is therefore also the data that may not have been sampled and included in the statistics histograms. This sort of issue is one of the reasons it can be critical to update your statistics more regularly than the built-in automatic thresholds.
We’ll look at the problem itself, but also some of the mitigations that you can take to deal with it within SQL Server.
Click through for more detail.