Your substrate will be an alkyl halide (or some other good leaving group) Using a sterically bulky base like t-BuOK attacks the less-substituted beta-proton, yielding the Hoffman product (a less-substituted alkene). A non-bulky base like NaOH or NaOEt will attack the more-substitued beta-proton of the substrate, yielding the more stable Zaitsev Product (a more-substituted alkene)
