I was initally surprised when NBC gave Chase the back 9 a few months ago since it had much lower ratings than other shows given extra episodes and it wasn't showing signs of improving ratings.
Now, NBC has backtracked, seeing as Chase has only done worse since then, and as the Hollywood Reporter reports, Chase will get 4 less episodes than planned.
It's also worth noting that Chase is moving to Wednesday, 9 PM for the midseason.