allow a scorecard to count the number of tags in a field and incorporate that into the score

This is a spin-off to the ideas that request that "custom fields" be incorporate-able into a score. It would be great if it wasn't just hard-entered integers, but anything that could be counted.

For example, we use a tag field to indicate which of our clients request a feature. It would be great to be able to set a score to count the number of tags and incorporate that value.