Hi Graptemys,

[adding a generic name wouldn't reflect reality and wouldn't help anyone find the field.]

Alas, neither nominatim nor the current popular tile generators do a great job at helping someone find unnamed baseball fields.  This is even truer on a visual level for rectangle-shaped soccer vs. american/canadian football fields; at least a baseball field shape is somewhat recognizable.

I totally understand and accept that we shouldn't tag for the renderer, but it's so tempting sometimes.
 
[noname=yes seems better than adding a generic name]

You just taught me today about the existence of `noname=yes`.  That would make perfect sense.   I've consequently de-baptized the Parc du Père-Marquette baseball field in changeset https://www.openstreetmap.org/changeset/140392873 — thank you for your input on this.  I plan to undo those inappropriate namings I've done in the upcoming weeks.

[There are now overlapping ways for `leisure=sports_centre` and `leisure=pitch`]

This is on purpose.

The `leisure=pitch` is for the baseball field itself, while the encompassing `leisure=sports_centre` is for the “whole baseball location” including bleachers, related buildings such as locker rooms, associated fences not tightly wrapping the baseball playing field itself, dedicated toilets, restaurants, dugouts, bullpens, drinking fountains and so on.

I've taken this problem of creating an explicit “relation” between the baseball pitch and its “facilities” to the community a couple of weeks ago and though there seems to be no perfect way for indicating the relationship, `leisure=sports_centre` appears to be the de facto standard for smaller soccer grounds in Europe with the same constraints.  See the discussion on 
https://www.reddit.com/r/openstreetmap/comments/15j677l/mapping_smaller_baseball_grounds_with_facilities/ if you're interested.

Have  a great weekend,