What is the collective noun of pitcher?

There isn't a single, commonly accepted collective noun for pitchers. However, here are some options you can use, depending on the context:

General:

* A set of pitchers

* A collection of pitchers

* A group of pitchers

* An array of pitchers

More specific:

* A battery of pitchers (used in baseball)

* A line of pitchers (used for pitchers in a bar)

* A display of pitchers (used for decorative pitchers)

Ultimately, the best collective noun depends on the specific situation and what you want to emphasize.