屡试不爽

well-tried / time-tested

time and again / repeatedly / frequently

to test / to try / experiment / examination / test

no; not so / (bound form) not; un-

not well / out of sorts / in a bad mood / without discrepancy / accurate

bright / clear / crisp / open / frank / straightforward / to feel well / fine / pleasurable / invigorating / to deviate