If Russia could once described as a riddle wrapped in a mystery inside an enigma, then the biennial battle for the three Metropolitan Water Reclamation District commissioner positions whose term ends could be described as the obscure wrapped in the arcane inside the absurd.

Every 2 years, while a flock of obscure politicians battle tempestuously for the posts -- which pay $45,000 annually, have a large office staff, require attendance at two meetings per month, and oversee an annual budget of $750 million -- the voting public pays scant attention. In these Democratic primaries, it's the blind leading the blind. Voters have no idea who they're voting for, so "random factors" like ballot position, gender, race, ethnicity and election day palm card endorsements usually trump qualifications, media endorsements, incumbency or being slated by the county Democratic organization. Also, an Irish surname is especially helpful.

The 2004 Democratic primary, featuring 11 candidates, produced a rarity: The three incumbents won. But, as they say, it ain't over until it's over, so a bunch of the 2004 losers are already strategizing and positioning themselves for the 2006 Democratic primary, in which another three MWRD commissioners will be nominated.

Why all this interest in an obscure job? The district employs 2,400 people to manage its water treatment operations, but most are covered by civil service, so commissioners cannot build a precinct army. But there are nearly 100 summer jobs, dozens of temporary jobs and gigantic helpings of contractual pork. The "Deep Tunnel" project, to alleviate water pollution and prevent flooding, has a price tag of $3.2 billion, and it is the president and general superintendent who decide which contractors get picked. And those contractors are expected to donate liberally to Mayor Rich Daley and his anointed Democratic candidates. The current president, Terry O'Brien, and the current superintendent, Jack Farnan, are Daley loyalists. In fact, Farnan grew up in Bridgeport, in Daley's 11th Ward.

Foremost among the 2006 contenders is attorney and political consultant Frank Avila, who finished fourth in 2004, just 38,745 votes behind Commissioner Gloria Majewski. His father is water district Commissioner M. Frank Avila, who won his job in 2002. Also poised to run again are 2004 losers Brendan O'Connor, Xochitl "So-She" Flores and Lewis Powell.

The 2006 primary will be especially chaotic, as two of the three incumbents whose terms are ending -- Harry Yourell and William Harris -- are expected to retire. That leaves O'Brien, first elected in 1988, as the only incumbent on the ballot. And being president is no guarantee of renomination, as former presidents Nick Melas and Tom Fuller lost in 1992 and 1996, respectively. Harris is black, so his replacement on the 2006 slate will be black, and Yourell is a suburbanite, so his 2006 replacement likely will be Barrett Pedersen, the Leyden Township Democratic committeeman.

Cook County is now so overwhelmingly Democratic that the primary is the election; a Republican last won a commissioner's post in 1972.

Here's a look at how those "random factors" affected prior primaries:

1984 (five candidates): Amid the Washington-Vrdolyak "Council Wars," Fuller, who is black, was dumped, and Aurie Pucinski, incumbent Joanne Alter and Juan Cruz were slated. Fuller, with strong black community support, topped Cruz. In a special election for an unexpired term, the Vrdolyak-led party slated black Iola McGowan, but she was beaten in the primary by Gloria Majewski. The significance: For the first time ever, slated candidates lost.

1986: (eight candidates): The slate consisted of incumbents Melas, Majewski and Lou Viverito, and they were 3-4-5 on the ballot. Nancy Drew Sheehan, a woman with an Irish surname was first, and she beat Viverito. The significance: Ballot position and gender came into play.

1988 (10 candidates): Interest in the job is picking up, as ambitious politicians understand the "random factors" situation. O'Brien was first on the ballot, and the slate of Yourell, Joe Gardner and incumbent Jim Kirie was 6-7-8. Gardner, who is black, got strong support from his base, but O'Brien's ballot spot and Irish surname doomed Kirie. The significance: Incumbency means less, as Kirie, a commissioner since 1970, becomes the second incumbent to lose.

1990 (eight candidates): The slate consisted of Fuller and past losers Kirie and Viverito; they were 2-3-4 on the ballot. But Frank Gardner was first, and Kathy Meany was the only woman running, and those two, plus Fuller, were victorious. The significance: Meany proved that there is a large gender vote for female candidates.

1992 (11 candidates): This was the "Year of the Woman" in politics, and the MWRD primary was no exception. The slate consisted of incumbents Melas, Majewski and Sheehan, who were 3-4-5. First on the ballot was Patty Young, and she got more votes than Melas. The significance: Three women won.

1994 (22 candidates): The stampede is now on, with an unofficial black slate, a woman's slate and a Polish slate. The three incumbents (O'Brien, Yourell and Joe Gardner) were slated, and they drew ballot spots 10-11-12, but because the ballot was so cluttered, they triumphed. The significance: In a huge field, party support is critical.

1996 (13 candidates): The slate consisted of incumbents Fuller, Meany and Frank Gardner, and they were 5-6-7. But Fuller was then being investigated by the U.S. attorney in a bribery probe, and he fell to Cynthia Santos, who was listed first and who had the benefit of being a woman with the same surname as city Treasurer Miriam Santos. The significance: It's first and female again.

1998 (14 candidates): It should have been a slam dunk for the slate, consisting of incumbents Majewski and Sheehan, along with Proviso Township Committeeman Gary Marinaro, with the 1-2-3 spots on the ballot. But Barbara McGowan, an aide to the late Commissioner Joe Gardner who is black, was listed last, and she campaigned hard in her base and topped Marinaro. The significance: For the first time, being last on the ballot was shown to be an asset.

2000 (12 candidates): It seems like O'Brien and Yourell always manage to run in the right year. The slate (incumbents O'Brien, Yourell and Harris) was 6-7-8; M. Frank Avila was first on the ballot, and John McNamara was last. Only two women were running, but neither had an Irish surname. There was no black slate, but Harris, who is black, got 30,000 more votes than Yourell, with O'Brien finishing first, Avila fourth and McNamara fifth. The significance: The slate won, even though the field was smaller than in 1994. In the primary for a vacant seat, the slated Marty Sandoval easily beat Quinn Avila (another son of M. Frank Avila) and Lynn Carmody (a man with a name that could be a woman's and an Irish surname). Sandoval became the first Hispanic MWRD commissioner.

2002 (nine candidates): The slate, consisting of incumbents Meany, Santos and Sandoval, drew lines 1-2-3, and they looked like easy winners. But Sandoval also had filed for state senator, and he was quoted as saying that he would resign as commissioner if elected senator. M. Frank Avila was running again, and he was last on the ballot. Avila's son Frank filed a federal lawsuit arguing that Sandoval was disenfranchising voters by running for a job he wouldn't keep; Sandoval argued that the water district was a part-time post and that he could keep both jobs if he wanted. But before the primary, Sandoval quit the MWRD race. Black committeemen backed Meany, Santos and former alderman Jesse Evans, and suburban white committeeman backed Meany, Santos and Jim Sheehan, the Palatine Township committeeman. But M. Frank Avila prevailed, topping Sheehan by 2,605 votes.

2004 (11 candidates): Hoping to replicate his father's performance, Frank Avila got the bottom ballot spot, and the slate (incumbents Majewski, Young and McGowan) were 4-5-6. Black committeemen pushed Young, McGowan and Powell, a black attorney. O'Brien endorsed O'Connor, who was third on the ballot. "So-She" Flores, an aide to Alderman Manny Flores (1st), whom Avila had helped elect in 2003, was first on the ballot, her nickname reminding voters of her gender.

Avila worked hard to line up party endorsements, and he got the backing of such powerhouses as Aldermen Dick Mell (33rd), Bill Banks (36th) and Ed Burke (14th), but the support of U.S. Representative Bill Lipinski (D-3) never materialized. In Chicago, Young, whose name has always been a big draw in the black wards, finished first, with 170,840 votes. McGowan was second with 161,283, topping Majewski 3-1 in most black wards but running surprisingly well in white wards, and Majewski was a distant third, getting 119,931 votes, with most of her support coming from white wards.

Avila got 99,902 votes in Chicago, just a shade more than Flores' 97,330; O'Connor had 78,065, and Powell 83,744. Avila and Flores ran about even in the Hispanic wards, but Avila ran behind McGowan inmost white wards. The significance: An Irish-surnamed black female candidate (McGowan) is unbeatable, as is a neutral-surnamed white female candidate (Young), whose name could be that of a black candidate.

Avila will be back in 2006. His father ran three times before he won. But, given the district's random factors, a good showing in one primary does not necessarily presage victory in the next.