Hit-and-miss

Tom's attempts to guess the market were hit-and-miss.

Source: tatoeba (8979606)

The novel ML-based approach to this problem is still very hit-and-miss.

Source: tatoeba (13627749)

But garbage, ashes, tin cans, rubbish, paper, packing, stable refuse, things which go so far to make a community less lovely and less livable are gotten rid of in the most hit and miss fashion, if at all.

Source: wiktionary

The upgrade from Channel 4 cult hit to Netflix blockbuster gave Charlie Brooker’s hit-and-miss dystopia anthology Black Mirror bigger stars, a bigger budget and, most notably, a far bigger audience.

Source: wiktionary