the ordinary and necessary expenses paid or incurred during the taxable year in carrying out the taxpayer's gambling business could be deducted under the terms of §162(a). Importance Commissioner v. Groetzinger explains that in deciding whether an activity is a trade or business courts need to examine the facts on a case-by-case basis, looking into whether the taxpayer devoted his or her full-time efforts towards the activity on a regular, continuous, and substantial basis. See also Internal Revenue Code section 162(a) List of United States Supreme Court cases Lists of United States Supreme Court cases by volume List of United States Supreme Court cases, volume 480 List of United States Supreme Court cases by the Rehnquist Court References Further reading External links United States Supreme Court cases United States Supreme Court cases of the Rehnquist Court United States taxation and revenue case law 1987 in United States case law