There are many metrics to measure the effectiveness of a testing team. One is the rejected defect ratio, or the number of rejected bug reports divided by the total submitted bug reports. You may think you want zero rejected bugs, but there are several reasons that’s not the case. Let's look at types of rejected bugs, see how they contribute to the rejected defect ratio, and explore the right ratio for your team.
A good team likely is trained to consistently report defects as accurately and promptly as possible. This means that over time the bug backlog builds up, and looking for what bugs to fix starts to seem like searching for a needle in a haystack. The best way to keep your tracker under control is to improve the quality curve earlier.