One hundred is a nice round number from which to try and extrapolate trends and as it happens Ireland and France are about to complete a century of Test matches against each other.
Sunday's Guinness Six Nations match at the Aviva Stadium will be the 100th between the two nations at senior Test level but from an Irish point of view, it's one in which the French have tended to come out on top, even if Ireland dominated the early encounters until 1930 when France began a run of three wins in a row before asserting real dominance from the start of the Swinging Sixties.
In the 99 previous meetings dating back to 1909, France have won 57 to Ireland's 35 and Paris especially was a tough fortress to breach for successive Irish sides.
Indeed, the famous Paris triumph fueled by Brian O'Driscoll's hat-trick in 2000 saw Ireland end a 17-game streak without victory in the head-to-head both home and away, with the winless run in the French capital alone standing at 28 years up to that juncture.
The years have been kinder to Ireland since the turn of the Millennium although Paris still remains a tough nut to crack in the Six Nations era, with 2014 and the last-gasp Johnny Sexton-inspired 2018 win being the only Irish victories there since 2000.
Similarly, as Sunday's game approaches, France have increasingly found Dublin difficult in that time period, especially in the last decade. Here are how their last five Six Nations visits to the Aviva Stadium have panned out as the dial turned in Ireland's favour.
2011 (France win)
While 100 is a nice round number, so is 10. That is the number of years since the French came to Dublin and earned a victory. Indeed, 2011 saw them win twice at the Aviva Stadium but the second of those was a pre-World Cup warm-up that August.
The February fixture, however, was the second game in Les Bleus' defence of the Grand Slam title won the previous year.
As the game rolled around, Ireland had only beaten France once since 2003 - the famously tense 2009 Croke Park match on route to the Grand Slam - and Declan Kidney's side were coming into it off the back of a narrow two-point win over Italy when another Ronan O'Gara drop goal - as a 65th minute substitute for Sexton - had rescued Irish hopes.
Three points separated Ireland and France on 13 February but this time there would be no rescue act. While Kidney's team came out on top in the try count with Fergus McFadden, Tomas O'Leary and Jamie Heaslip's efforts more than cancelling out Maxime Medard, it was the penalty count that titled the game towards Marc Lievremont's squad.
Morgan Parra, unerring from the boot, nailed five from five, with Dimitri Yachvili scored another plus a conversion to hold off Ireland's challenge in the 25-22 result.
France may have won the battle but the 2011 war proved frustratingly inconsistent for both teams. Ireland would suffer defeat to Wales but then rally to deny England a Grand Slam and Triple Crown, while the French would lose to Italy on the penultimate weekend.
Three Irish players from that matchday squad are still involved in this year's Six Nations squad: Keith Earls, Johnny Sexton and Cian Healy.
In contrast, the number is zero for France - a sign of the turnover after a fallow decade and the trust in youthful talent that has made them Six Nations favourites in 2021. Indeed, they only have three players aged 30 or over in their current squad and all first earned international recognition from 2012 onwards.
2013 (Draw)
Two years on and while Kidney was entering what would be his final year as Ireland head coach, France were into the second year of the Philippe Saint-Andre experiment - he has been speaking to RTÉ's Game On in-depth this week - as their fortunes tumbled down the Six Nations table.
But 2013 was the nadir as they received the ignominious wooden spoon in a campaign which included another loss to Italy, while the only win came on the final week against an average Scotland side.
Ireland, though, were also coming to the end of a cycle with the fall almost as brutal as the French's after what had been a thrilling win over Wales on the opening day. Like Les Bleus, Kidney's side went on to lose to a buoyant Italy in a campaign featuring just that one aforementioned win.
So it was fitting that when they did meet at the Aviva Stadium on match week four, it would end in a draw with Heaslip and Louis Picamoles exchanging the only tries in a 13-13 draw which saw the home side fail to notch a single score for the final 48 minutes of play. Ultimately, Ireland avoiding defeat just about spared us the wooden spoon, having finished level on points with the French.
2015 (Ireland win)
Things were looking up for Ireland two years on. Under Joe Schmidt's tutelage, Ireland had won the 2014 Six Nations title, beating France in Paris in the process.
And they would defend the championship title in a World Cup year when a pool clash against the French was to loom later that October.
So that made the Valentine's Day 2015 date all the more crucial as a psychological boost and a marker to lay down for the winner.
With France still struggling in the Saint-Andre era, Ireland made the most of it with an 18-11 win at the Aviva Stadium.
In contrast to 2011, France won the try count thanks to Romain Taofifénua's effort 10 minutes from the end. But it was a game won from Johnny Sexton's boot as his five penalties, coupled with another from Ian Madigan saw Schmidt's side pick up a crucial victory on route to a second consecutive title.
And when the sides met again eight months later in the final World Cup pool match to decide the pool-topper, Ireland repeated the trick with a 24-9 victory - the first three-in-a-row over the French since the early 1970s.
But it was an ultimately pyrrhic victory as Argentina outclassed Schmidt's somewhat depleted team in the quarter-finals.
2017 (Ireland win)
France had gained some measure of revenge with a narrow one-point win in Paris four months later back in the familiar surroundings of the Six Nations but Ireland would restrict them to three Camille Lopez penalties just over a year after that.
Conor Murray's try on the half hour mark would prove crucial in the 19-9 win along with Sexton's penalties and a drop goal that would prove to be a slightly forgotten warm-up act to 2018's more memorable 'le drop'.
2019 (Ireland win)
The 2020 Player of the Championship Antonie Dupont had not yet been capped by the time of the 2017 game but the sprinklings of a French revolution were increasingly evident by the time the 2019 encounter with a Grand Slam holders Ireland rolled around.
An experienced Ireland side with its own infusion of emerging talents had the measure of the visitors, triumphing 26-14 thanks to tries from Rory Best, Sexton, Jack Conan and Earls.
But for France it would be an important learning curve in the development of Dupont and the talented 10 Romain Ntamack who both started that day - a year in which the latter would win World Rugby Breakthrough Player of the Year.
He won't be involved on Sunday through injury but nevertheless it's France who go in as favourites which goes to show how quickly their fortunes have flipped thanks to their burgeoning base of young talent.
Whether Ireland can prevent the French from ending a 10-year winning run in the tete-a-tete at Lansdowne Road is one we'll find out soon enough.
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