The two club rivals Lionel Messi has faced most often in his record-shredding career are Real Madrid and Atletico Madrid.
Across 72 matches against those La Liga foes, the Argentina international has scored 52 times and won 38 of them. Extraordinary stats.
The English teams who have most often tried to figure out a way to smother Barcelona's No. 10 in the Champions League are, in order, Chelsea, Arsenal, Manchester City and Manchester United.
Against Arsenal, City and United he's scored 17 goals in 16 games -- winning 11 times and losing only three. If anything, that amounts to a still more stellar performance level than his "Messifying" of the two Madrid giants. But then there is Messi against Chelsea, which, for a host of reasons, has produced one of the great anomalies of modern football.
It is relatively well known that not only has Messi never scored against them across eight games (655 minutes) of football but he has only beaten Chelsea once -- which, on Thursday, will be exactly 12 years ago. It's astonishing.
Given how Messi has, one way or another, embedded his DNA on every other major rivalry during his footballing career this anomaly is like Lewis Hamilton failing his driving test or Britain's Bletchley Park World War II Enigma code-crackers struggling with a basic Sudoku.
And you can't simply assign the strangeness to a special "Chelsea' tactic." Over the 12 years since he last beat them, while there have been a variety of reasons for him not scoring, Chelsea have used two different keepers, three different managers and a variety of strategies.
What's that you say? You want a sidebar with more spicy sauce on the meal? Okay. This will be the first time that Messi has faced Chelsea with Thibaut Courtois in goal.
The Belgium international had a no-waffle introduction to life under the yoke of Messi in La Liga. His first three matches against Messi while minding the net for Atleti resulted in three defeats, 11 goals conceded and six of those goals from No. 10.
But Courtois then went his next seven games for Los Rojiblancos, plus an Argentina-Belgium international, without conceding even a sniff to Messi. This makes his attempt to maintain Chelsea's shackling of the otherwise ultra-prolific forward all the more tantalizing this week. It's now 720 minutes across five-and-a-half years since Courtois conceded to Barca's greatest-ever player.
In all honesty, the stage was originally set for this to be an utterly different tale of the tape between the Catalans' all-time leading scorer and the Blues who've given him the blues.
Cast your mind back to that first meeting between Messi's usually irresistible force and his immovable object Chelsea.
When Frank Rijkaard's Spanish champions travelled to Stamford Bridge for the first knockout round of the Champions League in February 2006, Chelsea were the Premier League holders and boasted a 12-point lead over second placed Manchester United in that season's title chase. Moreover, it was almost exactly one year on from the 4-2 power-play drubbing which Jose Mourinho's turbo-charged Blues had handed out to Rijkaard's Blaugrana.
Xavi was absent injured, Andres Iniesta left on the bench and, for the purposes of this damning statistic, Messi didn't score. But his display, on what was only his second starting appearance away from home in the Champions League, marked him down as peerless among his age group -- and a footballer whose deep reserves of character matched his talent.
Asier del Horno was sent off for a series of fouls on Messi, one of which left purple and blue stud marks high up on the inside of the Barca talisman's thigh.
The pitch that night was a cabbage patch and until Samuel Eto'o's headed winner the teams exchanged own-goals. But Messi, aged just 18 and with only 10 La Liga starts to his name, was jaw-droppingly good.
I'll let Marca's peerless writer on the night, Santiago Segurola, give you a flavour of what that February delight in West London was like.
"In a rarely seen show of intelligence, skill and courage Messi tore Chelsea apart to the astonishment of the English fans," Segurola wrote. "When they booed him there was dread at his overwhelming class.
"You shouldn't be able to dominate a football match of this calibre aged 18. Football has few precedents and those who come to mind were geniuses: Pele, [Diego] Maradona, [Johan] Cruyff... George Best"
Mourinho set running a terrible calumny which would haunt him four years later when, in charge of Real Madrid in his first Clasico, he suffered a 5-0 defeat and the Camp Nou's 99,000 hoarse hoard chanted: "Ve te al teatro... Mourinho ve te al teatro..." [Off you go to the theatre, Mourinho].
Those chants were a reference to the Portuguese calling Messi "theatrical" for how he tried to avoid Del Hornos's kung-fu style, thigh-high flying boot.
A couple of weeks later against Chelsea, the little superstar in the making lasted 25 minutes before departing, in tears, because of a then-habitual hamstring problem. Medics reckoned it would need a month to heal -- it ended up costing him a chance to participate in the 2006 Champions League final win against Arsenal.
No matter whether he scores, or plays 90 minutes, Messi against Chelsea always seems to turn up something pretty seismic. A couple of Champions League group games ebbed and flowed without him hitting the net, and without either side playing at full tilt, but then along came the semifinals of 2009.
By then Messi was a maestro -- established, certified and played in the middle of the pitch by his new coach Pep Guardiola.
The first game, with Chelsea brisk and physical under the strategic command of Guus Hiddink, ended 0-0 at Camp Nou.
Stamford Bridge was epic for the second leg. Penalties not given; a red card wrongly given [to Eric Abidal]; Michael Essien's thunderous opening goal; Carles Puyol in the stand telling Guardiola's lieutenant Manel Estiarte "it's cool, it's cool we'll still go through" as the minutes ticked towards 90. And the Blues stood on the edge of their second consecutive Champions League final.
But as normal time ended, Dani Alves hoisted the ball into the box, Eto'o tried to control John Terry's glancing header but the ball slid off his boot and fell to Messi -- the guy who "doesn't" score against Chelsea.
Until that moment, and from that moment till now, his calling card had been the dribble; the wriggle, dart, twist and dagger in the heart of the keeper with a left-footed shot. But Messi didn't think twice and laid the ball off perfectly to Iniesta to crash it into Petr Cech's top left-hand corner.
Messi's pass put Chelsea out. And put Barca into a final which saw them complete their first ever Treble. But the pair of matches which complete Messi's odd octet against Chelsea are the oddest.
Chelsea would go on to win the 2012 Champions League final -- delivered, as promised, by Roberto Di Matteo to his boss Roman Abramovich. However there were spells during the semifinal first leg at the Bridge, when nobody, Robbie and Roman included, would have given Chelsea a chance.
Messi was like a sorcerer: when he pointed that wand of a left leg, the ball went where it was supposed to. The trouble was that none of his teammates could match him. His move with Iniesta put Alexis Sanchez through, but the Chilean hit the bar; Messi's dribble past three defenders ended with Cesc Fabregas shanking a shot with the goal gaping; then his dispossession of John Obi Mikel and sprint towards Cech again left Fabregas one vs. one, but his dink over the keeper was cleared off the line by Ashley Cole.
So it went on. Messi's chip to Puyol brought Cech's best save; his sprint and dribble ended with Pedro hitting the post.
But Chelsea kept him out. In fact, they targeted Messi, as Mourinho was then doing for Real Madrid, in the belief that if he were to be robbed in possession then Barcelona would be vulnerable. And so it proved. Just before the break Frank Lampard caught Messi, nicked the ball perfectly, fed Ramires and Didier Drogba gave Chelsea a 1-0 win to take to Camp Nou.
The second leg simultaneously put Chelsea on course to win their only Champions League, ended the reign of Pep Guardiola at Barca and caused Gary Neville to squeal his astonishment at Fernando Torres' 92nd minute equaliser at a pitch only dogs could hear.
But during a ragged, torrid, exhilarating game where Ramires scored one of the great European goals, Messi thudded a penalty -- which would have left 10-man Chelsea trailing 3-2 on aggregate after goals from Sergio Busquets and Iniesta -- on to the crossbar and it ended 2-2 with Chelsea the ones who went through 3-2 on aggregate.
Headlines, as Xavi pointed out over the last few days when critically analysing Cristiano Ronaldo against PSG, go to the scorers and winners but, in his view, don't tell the full tale of who has played well and whose influence has brought the game to life.
Perhaps that's a motif for Messi against Chelsea. Some of his efforts have been epic; some of his goal-free efforts have, nevertheless, brought his club to glory. But it's always been worth watching, which is vital in any rivalry.
I vividly remember English pundits gleefully reminding Messi in 2009, ahead of the Champions League final in Rome, that he'd never scored against a Premier League side. And Italians doing the same back in September about his eternal goal-drought against Gigi Buffon.
He put both of those anomalies to bed, or rather the back of the net. Something I fully expect him to do over the next 180 minutes against Chelsea. Don't you?