To those who watch and practice the peculiar politics of Rockville, the collision of tradition, viewpoint and style in the election campaign between Mayor Steven Van Grack and challenger Douglas M. Duncan seemed inevitable.

Van Grack, 39, was an unknown two years ago when he upset Rockville's small-town political ways with a well-financed, sophisticated campaign that edged out two longtime city powers. Now, he is locked in a bitter fight with Duncan, 32, a product of the political establishment who pledges to restore simpler values to city government.

Development -- the commercial explosion that has made Rockville Pike synonymous with gridlock and is viewed by some residents as threatening the quiet neighborhoods of Maryland's second largest city -- has emerged as a key concern of voters in the nonpartisan Nov. 3 contest. And, in Montgomery County, where planning and zoning have become a local religion, the slugfest in the county seat has attracted the interest, as well as the financial involvement, of politicians, developers and others beyond Rockville's borders.

Much as campaign contributions and tactics fueled controversy in last year's fierce race for Montgomery County executive, questions about the money Van Grack has raised and charges lodged by his opponent have provided ammunition in this year's intensely personal campaign. With eight days remaining before the election, both sides concede that the outcome is a toss-up.

Although the mayor counts for only one vote on the five-member City Council, Van Grack used the position to become an undisputed figurehead for the city. In Rockville, a once-sleepy community that has begun to confront urban problems, his leadership has become fodder for Duncan, who for two years on the council has been a constant sparring partner. The two differ on several key issues, including rent control, the police department, the city manager, and school boundaries set by the county.

In their appeals to the city's 23,731 registered voters -- nearly three times the number registered to vote in the election two years ago -- Van Grack and Duncan have tried to portray themselves as protectors of city neighborhoods and advocates for limited growth.

Van Grack is unabashedly brash. Perhaps best known for his 1985 jog down Rockville Pike, during which he outpaced rush-hour traffic to call attention to development concerns, the incumbent has a full-time paid campaign manager, campaign headquarters and the services of a political consulting firm. His message that the city has accomplished much under his two years of leadership is carried in direct mail.

Duncan is decidedly low-key. Three times elected to the City Council, Duncan in 1985 received the highest vote total of any candidate in Rockville history. He is running his campaign out of his home with the volunteer help of family and friends and with the support of four former mayors. His message that Rockville's small-town values are "at risk" under Van Grack is delivered door to door.

Van Grack, a Rockville lawyer who raised an unprecedented $30,000 in his 1985 run for the $8,000-a-year job, has come under fire after raising a larger sum this year, with an estimated one-third of the funds coming from the development community. Van Grack has raised an estimated $40,000, more than three times the $11,554 raised by Duncan, a manager for AT&T.

And, in what Van Grack backers admit is a damaging development, an analysis by Duncan supporters revealed that the mayor's campaign aides altered the names of towns listed for some contributors in city campaign finance records, making it appear that a larger number of the contributions came from city residents.

Van Grack apologized for the reports, which listed 25 Potomac contributors as residents of Rockville, but he denied any intention to deceive voters, attributing the errors to his aides. Van Grack described the campaign contributions as a nonissue and "a smokescreen" used by Duncan to obscure his own changing positions on the issues.

In addition, Van Grack contended, the total of more than 340 contributors to his campaign "speaks well for me, not ill . . . . Rockville is not an island; it is part of Montgomery County and there is support for the city outside our walls, and that's good."

Duncan countered that Van Grack has taken what used to be a grass-roots political campaign out of the neighborhoods and handed it over to the political image-makers. "It's the same kind of slick, sterile, blow-dry politics that all of us have grown to distrust," he said.

Such rhetoric has made the campaign one of the most vitriolic in a city that prides itself on its tradition of nonpartisan elections, its progressive policies and participation in government by many of its 45,000 citizens.

As a bedroom community for many federal workers precluded from party politics, Rockville for decades selected its leaders in nonpartisan conventions dominated by insiders from local groups, such as the Alliance of Rockville Citizens and Independents for Rockville. That changed in 1985 when Van Grack, running as an independent, took advantage of the disarray in City Hall that followed the resignation of Mayor John Freeland amid conflict-of-interest charges.

Van Grack, a civic activist who had fought the development of a proposed office park, toppled the party network by defeating two of its most popular spokesmen in a three-way race.

In spite of his professionally run campaign and the advantages of incumbency, Van Grack is caught in a race that he concedes is "a whole lot closer than I imagined going in."

The mayor is on the defensive. At debates and in dozens of letters to local newspapers, Duncan supporters have attacked Van Grack about his contributions and his warm relationship with Gov. William Donald Schaefer, who is less than popular among many of the city's Democrats. Last year, many Rockville Democrats backed Schaefer's opponent for governor, then-attorney general Stephen H. Sachs.

Old-school Rockville politicians -- the heart and soul of the Duncan camp -- show particular disdain for partisan politics. So when the mayor held a $100-a-plate dinner and "town meeting" fund-raiser attended by Schaefer, the issues of money and partisanship were joined.

Van Grack sees his friendship with Schaefer as a key in getting state funding for city projects, including road construction the city is expected to undertake in the next two years. Duncan and the party regulars view the relationship as an intrusion into the city's traditionally nonpartisan government and criticize Van Grack for running to the governor to solve city problems.

The candidates largely agree on major development issues, with both saying they favor controlled growth balanced against the needs of neighborhoods. In recent weeks, Van Grack and Duncan have scrambled to draft new formulas to limit commercial development along Rockville Pike, the state's most lucrative retail strip.

Duncan, who is seeking to portray Van Grack as a candidate compromised by hefty contributions from developers, has been criticized by Van Grack supporters for what they say is his seeming endorsement of a proposed 750,000- square-foot commercial and residential development in one of the city's most congested areas. Van Grack firmly opposes the plan. Duncan said he will not take a stand on the project because no formal proposal has been made.

Adding to the race's uncertainty is a new method of voter registration in the city, which added more than 15,000 names to the rolls.

The outcome will help shape the political careers of two Democrats widely seen as having futures beyond the Rockville city limits. Van Grack previously was mentioned as a possible candidate for the 8th Congressional District seat now held by Republican Rep. Constance A. Morella, and Duncan last year was courted by county Democratic operatives to run for the Montgomery Council.

"The dice are sort of being rolled here," said Keith Haller, the paid political consultant advising Van Grack.