For high schools across the country, March is traditionally the time for crowning state basketball champions. Not in Massachusetts, at least not this year. Hit by Proposition 21/2 tax cuts, schools throughout the state agreed to shorten this year's tournament (along with those in other sports) in a one-year experiment. The field was boiled down to four regional winners, then play awkwardly terminated. The cost of transporting teams cross-state supposedly makes continuing too expensive. But in a state the size of Massachusetts, shouldn't the cost of conducting semifinal and final games be recovered in gate receipts? If not, why start what you can't finish?