You're confusing a breathalyzer with a field sobriety test, the latter of which no one should agree to. It's the sort of test that asks you to walk straight, hop on one leg, allow an officer to use a flashlight on your eyes, or recite the alphabet backwards. They're designed to allow the officer to use their discretion to determine if you've failed rather than use an objective reading (like a breathalyzer).

Ask yourself why an officer would want to use a set of tests that require being subjective instead of deferring to a breathalyzer.