Rossies target net gains to end Mayo's run of shutouts
The one certainty about the law of averages is that, on the law of averages, it's bound to bring an abrupt end to every sequence, often when least expected.
Both Mayo and Roscommon will be conscious of that for very different reasons in Sunday's Connacht semi-final. Roscommon's fervent hope is for the law of averages to do its thing, while Mayo want it to snooze on.
It's all to do with the goal returns by both counties, which provide a fascinating backdrop to a clash which is generating big interest, arising from the Rossies' much-improved form this year.
Mayo haven't conceded a goal in the Connacht championship since the first half of the 2011 semi-final, when Galway's Paul Conroy netted from close range.
Since then, Mayo have gone 8hours and 46 minutes (remainder of the 2011 clash with Galway and the subsequent Connacht final against Roscommon), plus wins over Leitrim and Sligo (2012), Galway, Leitrim and London (2013) and New York (2014) without giving away a goal.
The impressive lock-out has not only featured a complete ban on goals, but also a low points giveaway, conceding an average of less than 10 per game in their last seven Connacht outings.
Adding to the challenge for Roscommon is the fact that they haven't scored a single goal against Mayo in their last five championship clashes.
Roscommon's last championship goal against Mayo, scored by Nigel Dineen, came late in the first half of a qualifier in 2002 in Castlebar. That's 6hrs 27mins without a Roscommon green flag against Mayo.
There were signs during the Allianz League that the Mayo defence wasn't as secure as last year, having conceded an average of 2-13 per game in Division 1.
Roscommon averaged 1-16 per game en route to the Division 3 title before hitting Leitrim for 1-18 in the Connacht quarter-final.