We've pored over previous election statistics, we've talked to the parties, we've watched their canvass teams in action but even the most seasoned political observers are finding West Tyrone almost impossible to call.
Sinn Fein's Pat Doherty is supremely confident, the SDLP's Brid Rodgers has superstar status on the streets, and anti-agreement Ulster Unionist MP Willie Thompson certainly can't be written off.
West Tyrone is a huge, sprawling constituency. It's largely rural - the main towns are Omagh and Strabane. It's at least two-thirds Catholic but an evenly split nationalist vote allowed Mr Thompson to slip in last time.
The SDLP and Sinn Fein are determined that won't happen again, and it shouldn't. Although Mr Thompson isn't a hate figure among Catholics, his firm anti-agreement stance has fuelled determination to remove him.
About 3,000 new voters - two-thirds of whom are said to be nationalist - are on the electoral register. Until the SDLP parachuted in its popular Agriculture Minister, Sinn Fein was a dead cert for the seat.
Its candidate is vice-president Mr Pat Doherty (55), who is from Co Donegal but represents West Tyrone in the Assembly. Sinn Fein's vote has been steadily growing. "We have done the spadework," says one canvasser. "Not even a high-profile Stormont minister can undo that at the 11th hour." He predicts Mr Doherty will poll 18,000 votes with 16,000 for Mr Thompson and 14,000 for Ms Rodgers.
The SDLP dismisses this. "There's a touch of magic to our campaign and the magic is Brid Rodgers," says a party worker. Rarely is a politician greeted with such affection. "Not your typical stuffy SDLP type," says a woman in Strabane. On a recent Ulster Television programme, the candidates were asked what two items they would bring to a desert island. Mr Doherty said his Irish passport and a pro-Irish unity argument for Tony Blair. "Liam Neeson and a bottle of Jameson's," said Ms Rodgers.
At the 1997 Westminster election, the SDLP beat Sinn Fein by 612 votes. In 1998's Assembly elections, Sinn Fein pulled almost 4,000 votes clear. But it was a case of the Sinn Fein vote actually increasing by only 1,400 while the SDLP vote fell by 3,000. About 1,300 went to Mr Paddy McGowan, a former SDLP member who fell out with the party.
Ms Rodgers believes she can win these votes back and secure the Alliance votes in the constituency. Alliance isn't running and is supporting her. She is also hoping for votes from pro-agreement farmers impressed by her handling of foot-and-mouth.
The SDLP has been subjected to widespread intimidation by Sinn Fein supporters during the campaign. Its posters have been destroyed and workers told their vehicles will be burnt if they don't leave the constituency. Yesterday, Ms Rodgers had eggs and at least one stone thrown at her in Lochmacrory.
A canvasser attempting to protect her was grabbed by the throat. On Saturday, the SDLP says a Sinn Fein member drove at an SDLP cavalcade in Dromore at speed, hurling abuse. Such actions are a sign that, despite their public confidence, Sinn Fein supporters are worried about West Tyrone.
Willie Thompson is hoping that if the nationalist vote splits evenly again, he can hold the seat. He is a decent, straight-talking politician. "I mean what I say and I say what I mean," he says. He shuns spin and hype.
The Irish Times inquires how his campaign is going. "Reasonably well," says Mr Thompson. It would be to his political advantage to present Sinn Fein as his main electoral rival but he admits he can't tell who is.
"Brid is well known and has had a very good ministry but the Sinn Fein electoral machine is ruthless. None of us can compete with it. They have bags of money." Mr Thompson believes pro-agreement unionist voters will support him to prevent a nationalist winning.