IT may not apply in every case, but, as a general guide to the achievements of a football manager, it is safe to assume that, if he presided over more wins than losses against Kerry, his term would be regarded as a success.
And since putting down an early marker is always a good way to go about managerial business, Jim Gavin knows that a Dublin win over Kerry in Killarney on Sunday would be quite significant.
Beating Cork in Croke Park last Saturday was the ideal start, but following it up with a win over Kerry in Fitzgerald Stadium would be an even bigger achievement.
Dublin's triumph in Killarney in 2010 was their first 'away' success over Kerry for 28 years, underlining just how difficult they have found it to take league points out of the Kingdom. It was also the start of a three-game winning run against Kerry culminating in the 2011 All-Ireland final victory.
Coming just six months after Dublin's 'startled earwigs' had been scattered to the four corners of Croke Park by Kerry in the 2009 All-Ireland quarter-final, the 2010 league win marked the beginning of a change in dynamic between the two great empires after a long period of Kingdom dominance.
Pat Gilroy undertook a significant overhaul of the Dublin squad after the 2009 embarrassment and was rewarded with a dramatic turnaround in their league fortunes, which helped make them a much more reliable championship force.
By the end of his four-year term, Gilroy's league/championship record against Kerry read: Played 6, Won 3, Lost 2, Drew 1.
A draw in the 2006 league was the best that Gilroy's predecessor, Paul Caffrey, managed from four clashes with Kerry.
Now, Gavin is getting an opportunity very early in his term to gain a psychological edge over Kerry, something which should never be undervalued. For, while Kerry may hold no major titles at present, they are still the yardstick by which most counties evaluate themselves.
There is also the anticipated Kerry bounce-back as they attempt to recover from the rare experience of having failed to score in the second half of a game, as happened against Mayo last Sunday.
There has been an over-reaction to that defeat, for while Kerry were surprisingly inert in the second half, it looked very much like one of those freak power failures that hits every county occasionally.
More is made of it when Kerry are involved, which is another example of the standards by which they are judged and, indeed, how they judge themselves.
They will now be doubly determined to strike back immediately in order to bring about some stability before the three-week wait for the third league game, and to give new manager Eamonn Fitzmaurice an early boost.
Dublin have been backed down to 15/8 favourites to win the Division 1 title in the belief that Gavin has targeted the league as an early priority.
It is a wise policy since consistent league form has been the precursor to September glory for every All-Ireland winner over the past decade.
That includes Dublin, who reached the 2011 league final where they lost by a point to Cork, before winning all six championship games in their march to the All-Ireland title.
Their league rebuilding had begun with five wins from seven games in 2010, which was a marked improvement on their return over their 10 previous campaigns in which they were often in the bottom half of the table. In fact, they slipped into Division 2 in 2008.
Interestingly, two consistent league programmes in 2010-11 were followed by a sloppy campaign last year, which yielded only three wins (Laois, Armagh, Donegal), while they lost to Kerry, Down, Mayo and Cork.
That indifferent form was blamed on a post All-Ireland hangover, but, as the season developed, it became clear that the malaise had buried itself much deeper into the Dublin psyche as they never recaptured the 2011 form in the championship.
Against that background, Gavin was always going to place heavy emphasis on making considerable progress in this year's league.
Dublin began the process most impressively last Saturday when hitting Cork for 1-18, the Rebels' biggest league giveaway since conceding 3-13 against Dublin in 2011.
With four of their final five games in Croke Park, Dublin are virtually certain to reach the league semi-finals, even if they lose on Sunday – but that in no way lessens the motivation to beat Kerry.
On the contrary, the desire to prove that they can win on the road against one of the most consistent forces in football provides an extra incentive.
As for Gavin, the prospect of taking his first test against Kerry eight days after his experimental side has already stood up to one significant test is very appetising.
As Gilroy discovered, league markers can be helpful later on, even against the likes of Kerry.