The current most popular way of tagging both of these features is with sport=batting_cage and sport=cricket_nets, which have 870 and 2789 uses respectively. There is also a wiki page for leisure=batting_cage, which has 232 uses.
Those discussing on github dislike the usage of sport= for these two features, but there should be some community input before any decisions are made, because the method of tagging that gets added to the id tagging schema will likely become the most popular.
One more question that can be discussed is whether larger batting facilities with automatic pitching (shown below) should be tagged the same way as regular batting cages you’d find next to a baseball field. The sport=batting_cage page suggests the automatic_pitch=yes/no tag for this.
leisure=practice_pitch was put forward as an alternative to leisure=pitch. It then allows you to use sport=cricket rather than sport=cricket_nets.
sport=cricket_nets has significantly more usage currently.
Personally I’m in favour of deprecating sport=cricket_nets to be replaced with leisure=practice_pitch + sport=cricket, but it needs a strong consensus to do so.
leisure=practice_pitch sounds elegant at a glance. However, it would be prone to confusion with practice diamonds next to the batting cages, full-size gridirons, and… parking lots:
Do we need a unified tag for both batting cages and cricket nets, or can they be separate leisure=batting_cage and leisure=cricket_net? If we need a unified tag, could it not be leisure=batting_cage, since both sports would send their batters into it? If not, is there a more generic term that doesn’t risk confusion with very different facilities?
To highlight from there, “practice pitch” can mean smaller full-sized playing fields used for practicing and practice matches. It’s unanswered, and abandoned. Proposal talk:Practice pitch - OpenStreetMap Wiki
Yes. In Ireland, many sports clubs have two pitches, a ‘good pitch’ for competitive games (usually with spectators) and a ‘back pitch’ for training (usually with limited numbers of spectators). Slightly ironically, the back pitch is more likely to have lighting, as evening competitive games are rare, but evening training (noting that it gets dark at 4pm in winter) is quite common.
I forgot to mention there’s (man_made=sport_feature +) =sport_feature originally for sports equipment Proposal:Pitch features - OpenStreetMap Wiki
It can at least be used for the literal cages and netted frame themselves?
Sure, every sport has specialized practice spaces, so the function is certainly comparable. To me the question is whether all these features are physically comparable. The practice diamond I mentioned earlier would seem to qualify as a leisure=practice_pitchsport=baseball just as much as the batting cage next to it, but any renderer or geocoder would need to distinguish these features from each other, let alone the nets or pitches of another sport. Likewise the back pitch is still a pitch, whereas a batting cage is not.