Deductibility restrictions on gambling winnings: expenses for winnings disallowed, limited exception for racehorse owners maintained for racing. A new provision disallows any deduction under the Act for expenditures or allowances when computing Income from other sources that consists of winnings from lotteries, games, races (including horse races), gambling or betting, but preserves deduction for an assessee who owns horses maintained for running in horse races; 'horse race' means a race upon which wagering or betting may be lawfully made.