Base, bidding pattern and min trip length all matter. Categories with a higher percentage of 4+ day FRMS trips get used less than categories with 3 day non FRMS. Throw in a few 2-3 day domestic trips and utilization is also higher. In general expect 2-3 short calls and 8 days of flying during your reserve obligation. There WILL BE outliers. Senior LAX 350 pilots bidding 4 day blocks T-F will have an entirely different utilization than a junior NYC 330 pilot on reserve F-W.

For complete analysis, ID the BSE you are considering, then check the daily trip coverage for the last 60 days and take notes. Wait another month or two and do the same. You will get a picture of how reserves get used.