Less than three years ago, board members at the New York Stock Exchange said former exchange Chief Executive Dick Grasso had performed well in his job. One of the directors, Treasury Secretary Henry Paulson, then the head of Goldman Sachs Group, went so far as to assign Mr. Grasso an "A+" grade, according to internal NYSE documents.

Still, the board decided to let Mr. Grasso go, a reaction to the outcry over the $187.5 million compensation package Mr. Grasso had amassed.

Mr. Grasso's job performance is about to go under the microscope again. A civil trial to decide whether his compensation was inappropriate could start as early as October. The lawsuit in that case, brought by New York state's attorney general, Eliot Spitzer, demands that the 60-year-old Mr. Grasso return some of the money to the NYSE, now a part of NYSE Group Inc.

Mr. Spitzer's case hinges on whether the head of what was then a not-for-profit organization should have earned such a big pay day. Mr. Spitzer says no, and bases that assertion on a 37-year-old New York state law that holds compensation must be reasonable and "commensurate with services performed."

(At the Treasury, a spokesman declined to comment.)

Legal findings aside, whether Mr. Grasso deserved all that money is a matter that continues to be debated in the court of public opinion, whose many judges are comparing what the Big Board was and what it has become -- essentially debating Mr. Grasso's legacy.

Much has changed since Mr. Grasso departed his cavernous office on the exchange's sixth floor. The Big Board has transformed into the for-profit company NYSE Group, which must confront the bottom-line concerns that all publicly traded companies face. And the new occupant of the CEO's office, John A. Thain, has embraced electronic trading, in direct contrast with Mr. Grasso's strategy of defending floor-based human traders against the march of computers.

Mr. Grasso kept the trading floor profitable at a time that most people considered it obsolete, says Benn Steil, director of international economics at the Council on Foreign Relations. But "he left the exchange very vulnerable," and "there was no diversification in terms of products."

Mr. Grasso almost single-mindedly focused on trying to ensure that the Big Board dominated stock trading. Mr. Thain, on the other hand, has looked for growth in areas that Mr. Grasso shunned, including derivatives and bonds.

Mr. Grasso's tenure as CEO brought much success. He kept the Big Board's market share of trading in its own listed stocks above 80 percent, even as rival Nasdaq Stock Market Inc.'s share of trading in its own stocks cratered. At the same time, he maintained the NYSE's dominance in listing the biggest U.S. companies and attracted major foreign firms, employing marketing savvy that brought corporate executives onto the floor to celebrate their stock offerings and primp for the cameras. Later, he won plaudits for helping reopen the NYSE just days after the Sept. 11 terrorist attacks.

"All I can look at is our market share, profitability," and the growth of the "non-U.S. franchise," Mr. Grasso says in reference to his tenure as CEO from 1995 to 2003. "I'll be judged by that." In an interview, Mr. Grasso agreed that Mr. Thain has taken the exchange in "a different direction." But he says his successor's strategy reflects "the competitive environment now."

Critics of the exchange's current direction also point to ways in which the Big Board has slipped since Mr. Grasso's departure. Its trading market share on the floor has slipped below 70 percent -- a three-decade low. And Nasdaq has poached several NYSE-listed companies, including Charles Schwab Corp. and Cadence Design Systems Inc.

Mr. Grasso's legacy could play into his trial, especially now that New York State Justice Charles E. Ramos has broken the proceedings into two parts, legal experts say. Justice Ramos first plans to rule on whether Mr. Grasso's pay was reasonable, separate from any questions about whether the pay process was flawed. Mr. Grasso's lawyers are appealing that decision, arguing the two questions should be decided at once by a jury, not a judge.

Still, the case will depend in large part on the numbers: Mr. Grasso, a native of New York's Queens borough, who started at the NYSE as a clerk in 1968, earned $97 million in total pay from 1995 to 2002. He also accumulated through his career more than $100 million in deferred compensation and retirement benefits. Mr. Spitzer has argued both the base pay and extra compensation were excessive, compared with the pay of other executives.

Mr. Grasso has countersued the NYSE for more than $50 million in pay he says he is still due. Should he win that amount, he has pledged to give away the entire amount.

He has defended his pay repeatedly by pointing out that the NYSE board approved it and believed he was doing a stellar job. According to a 2003 report prepared for the NYSE by law firm Winston & Strawn, the exchange exceeded the performance criteria set by its executives and board members by an annual average of 27 percent from 1995 to 2002. In 2001, the year Mr. Grasso earned a career-high $30.6 million, the NYSE exceeded the benchmark by 38 percent, paced by high marks in financial, market share and regulatory categories.

Gerson Zweifach, an attorney for Mr. Grasso, says his client left the Big Board in a good financial shape and notes the NYSE under Mr. Grasso investigated and reported suspected trader misconduct to the Securities and Exchange Commission. Last year, 15 former NYSE traders were indicted for allegedly short-changing investors from 1999 to 2003, while Mr. Grasso ran the exchange. Two of the traders have been found guilty of securities fraud. Two have pleaded guilty and a fifth was found not guilty. Mr. Grasso hasn't been named in any of the trading cases, but the NYSE last year promised to spend $20 million on new regulatory initiatives to help settle civil SEC charges that the exchange failed to police the improper trading during Mr. Grasso's tenure.

During his last years at the NYSE, Mr. Grasso also devoted more time to matters of corporate governance, aiming to improve investor confidence, observers say. He also worked on building a better backup facility for the exchange in case of another terrorist attack or other unforeseen disaster.