How many teeth should a ratcheting wrench have?

More teeth means a smaller swing arc, which matters in confined spaces. 72-tooth ratchets (5° swing) are standard on mid-range sets; 90-tooth (4° swing) and 120-tooth designs cost more but help in tight engine bays. Reviewers in the threads we read generally consider 72-tooth adequate for DIY and 90+ tooth worthwhile for professional mechanic work.