You can often pinpoint the very moment a title was won or lost.
It might be a single match, such as Borussia Dortmund's win over Bayern Munich 17 days ago, or a speech, such as Rafael Benitez' notorious "fact rant" in 2009 that was promptly followed by a draw with Stoke.
The current Premier League season has had several moments that looked as though they might qualify as title-deciders, but as the title is still undecided the moment of truth must still be to come. It will probably come on Monday.
With only three rounds to play before the schedule comes to a close, Manchester City and Manchester United are set to clash in a local derby that will almost certainly determine the destination of this season's championship.
United are three points ahead of City coming into the match, but City have the superior goal difference and with a win would pull level on points and hold the tiebreaking criteria.
United manager Sir Alex Ferguson, following last weekend's 4-4 draw at home to Everton, set the tilt up as "probably the most important derby game" in his time at Old Trafford. Manchester City goalkeeper Joe Hart, whose side won 2-0 at Wolves later the same day, admitted City's title chances "are certainly a lot better than they were at the start of Sunday," when United's advantage atop the table was still five points.
United's draw with Everton, which came after the Toffees scored twice in the final seven minutes to wipe out a 4-2 United lead, was just the latest in a sequence of important moments that has kept momentum shifting back and forth between the Manchester giants the past two months.
It was, after all, only seven weeks ago that Manchester City were enjoying a five-point cushion in the standings.
But a 1-0 loss at Swansea -- seen at the time as the very instant United would overtake their local rivals for good -- saw them concede top spot for the first time in 2012, and by April 8 United had amassed an eight-point lead. If the Swansea defeat hadn't put an end to City's title hopes, Mario Balotelli's meltdown that afternoon against Arsenal surely had.
Less than two weeks earlier Balotelli -- a flashpoint of controversy all season -- had astonishingly turned up in Milan at the press conference introducing new Inter manager Andrera Stramaccioni, for whom the striker played at under-21 level. That same day City manager Roberto Mancini, instead of keeping tabs on his players, was visiting a monastery in Bosnia-Herzegovina.
The extraordinary lack of professional discipline on the one hand, and the absence of a manager during a vital week of the campaign on the other, seemed to combine to produce what had every appearance of being the very moment of a title contender's implosion. But then United lost to Wigan.
It was the Red Devils' first defeat since early January and just the second time all season they had been kept off the scoresheet. Shaun Maloney's well placed strike after cutting in from the left in the 50th minute suddenly breathed new life into the title race -- another moment -- and Manchester City responded by hammering West Bromwich Albion to cut United's lead to five points. After Sunday's results, the gap was reduced to just three.
And so we await the definitive moment of a topsy-turvy top-of-the-table title pursuit that has produced more than a few bends in the road. It's hard to imagine the winner of Monday's derby won't go on to lift the trophy two weeks from now. There simply aren't enough games for yet another moment to arise that we'll all look back on, and pinpoint, as the one that determined the winner, and loser, of the championship.
-- Manchester City is unbeaten in the four games Carlos Tevez and Sergio Aguero have started in attack.
-- Neither side has any new injury worries ahead of Monday's derby.