Des Berry: 'What is it about playing in France... and why do Leinster have such a tough history there?'
What is it about French clubs?
For stretches, Lyon looked like lambs to the slaughter at Northampton Saints on Sunday, only coming to life when the game was gone.
Leinster can expect those woolly pets to have the power-crazed bite of lions in their own lair.
The power of the parish can over-ride all else as Leinster know only too well from their experiences in France.
They will know what is coming in Lyon. It is something else to actually stop it.
The French League leaders should be brimming with confidence from their lightening start to the season, carving out eight wins from nine rounds of the Top 14.
They have had the benefit of playing six of those matches at home at Matmut Stadium de Gerland where the scalps of Stade Francais (43-9), Toulouse (22-12), Brive (59-3), Bordeaux-Begles (25-23), Pau (27-8) and La Rochelle (45-17) have been taken.
They simply do not know what it is like to lose there this season.
This has created a French-flavoured fortress, the sort of obstacle Leinster have always struggled to get around over there.
Overall, Leinster have played 25 Pool matches in France, losing almost twice as many (15) as they have won (8) with two draws thrown in.
December 7, 2002: MONTFERRAND 20 LEINSTER 23, Stade Marcel Michelin.
The love affair with Europe was not felt at first sight, as the Blues suffered six straight losses in five seasons to Toulouse (2), Stade Francais (2), Bordeaux-Begles and Biarritz Olympique from 1997 to 2002.
The initial breakthrough came against Montferrand, since re-christened Clermont-Auvergne, at the magical Stade Marcel Michelin, in front of a 10,000 crowd.
Even then, it took a star-studded cast, led by Brian O'Driscoll, Shane Horgan and Leo Cullen, to get the better of the likes of Richard Cockerill and Olivier Magne.
Speed merchant Denis Hickie swooped to land a try late on, which Brian O'Meara converted to solve the problem Leinster had encountered in France.
December 3, 2004: LEINSTER 92 BOURGOIN 17, Lansdowne Road.
December 10, 2004: BOURGOIN 23 LEINSTER 26, Stade Rajon.
In fact, it was in victory that Leinster absorbed their greatest lesson in how French clubs can simply defy all logic.
The province had just posted by far its' largest total in the Heineken Cup with a 92-17 humiliation of Bourgoin, notching 13 tries, three of them from their current assistant coach Felipe Contepomi.
One week later, they travelled to France amid ongoing criticism about Bourgoin's flimsy commitment to the Heineken Cup.
It just stoked the home fires, out-half Benjamin Boyet rewarding his ferocious forwards with fine field position.
Leinster had to fall back on the brilliance of Brian O'Driscoll for two tries, the second turning pending doom into four precious points.
December 10, 2005: LEINSTER 53 BOURGOIN 7, The RDS.
December 17, 2005: BOURGOIN 30 LEINSTER 28, Stade Rajon.
Once again, Leinster had put on a show in Dublin to dissect the hapless visitors, Rob Kearney picking up two of their seven tries.
Now, they had been forewarned of the Jekyll and Hyde identities of their hosts and were all set for what was ahead of them.
The common theme of a rocket-fuelled start came to fruition when Bourgoin quickly rattled off seven points.
A vintage Felipe Contepomi performance, producing 16 points came to nothing more than a losing bonus-point when Alexandre Peclier smacked the winning penalty in the 80th minute.
The excuse of complacency was a non-runner, based on what had happened in 2004.
With the best will in the world, these matches come down to fine margins.
Even through the golden years from 2009 to 2012, Leinster won two, lost two and drew one on their escapades in the Pool.
October 21, 2018: TOULOUSE 28 LEINSTER 27, Stade Ernest Wallon.
Just last year, Leinster should have known better when they were slow to settle at Stade Ernest Wallon, falling 11 points behind Toulouse in as many minutes.
The French giants, on their way back to European prominence, had the bit between their teeth and had enough left in their legs to strike for a breakaway try by Maxime Medard, the winning points arriving from Thomas Ramos's conversion in the 70th minute.
It served as a timely reminder, five months after Leinster had matched Toulouse's four European crowns, how they had become the target for others to aim at.
The majority of the men tasked with going to Lyon were at Stade Wallon last season.
They know what to expect.
LEINSTER POOL RECORD IN FRANCE.
Played 25; Won 8; Lost 15; Drew 2.
1997/1998: Lost to Toulouse 38-19.
1998/1999: Lost to Stade Francais 56-31; Lost to Begles-Bordeaux 31-10.
1999/2000: Lost to Stade Francais 39-6.
2000/2001: Lost to Biarritz Olympique 30-10.
2001/2002: Lost to Toulouse 43-7.
2002/2003: Beat Montferrand 23-20.
2003/2004: Lost to Biarritz Olympique 32-21.
2004/2005: Beat Bourgoin 26-23.
2005/2006: Lost to Bourgoin 30-28.
2006/2007: Beat Agen 25-13.
2007/2008: Lost to Toulouse 33-6.
2008/2009: Lost to Castres Olympique 18-15.
2009/2010: Beat Brive 36-13.
2010/2011: Beat Racing Metro 38-22; Lost to Clermont-Auvergne 20-13.
2011/2012: Drew with Montpellier 16-16.
2012/2013: Lost to Clermont-Auvergne 15-12.
2013/2014: Beat Castres Olympique 29-22.
2014/2015: Beat Castres Olympique 21-16.
2015/2016: Lost to Toulon 24-9.
2016/2017: Lost to Montpellier 22-16; Drew with Castres Olympique 24-24.
2017/2018: Beat Montpellier 23-14.
2018/2019: Lost to Toulouse 29-28.
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