Most Score errors have a unique error code, so we could just send a counter to statsd whenever one is generated. Errors are totally expected from malformed user input, but this can help us track patterns or systemic problems (like T289298). Also sending the page name and revid to debug logging would be nice too.
Customize query in gerrit
|mediawiki/extensions/Score||master||+121 -79||Simplify exception creation, track errors in statsd|