After many years as a mergers and acquisitions and securities lawyer, I began investing in special situations professionally in 1996. Although the strategy has evolved to include any sort of idiosyncratic trade around a specific event or catalyst, then it was basically merger arbitrage.
For the entire period prior to 2000, before such field leveling laws as Sarbanes-Oxley and Regulation FD, a special situations investor could outperform the market by exploiting the informational advantage that came from just researching harder.