It's more than the obvious, their shared Spanish looks, hair and complexion.
Both wear a face of slightly tortured-soul seriousness. They both seem like a man on a mission - suffering for a higher calling. Both have a bit of an air of martyrdom about them.
Both are reed thin, stringy super climbers, with silky rouleur style. Both could time trial with the best.
Both unafraid to have a go at the ogre-giant of their respective generations, the Boss who made most of the riders cower.
Both rode on emotion, in the moment. They'd attack again and again, with a style more energetic than smooth or powerful, dancing out of the saddle for seemingly infinite periods.
And both share a knack for the dramatic - man, could they pull off an exploit.
Yesterday it was the Pinto stringbean. Soloing to what looks like, barring some disaster, will be another Vuelta d'Espana victory.
What it reminded me of was Ocana's great escape - his 1971 Tour stage to Orcieres Merlete. The day Luis Ocana rode away from the 'invincible' Eddy Merckx in the mountains.
Like yesterday, it was unexpected. Looking at the stage profile, it wasn't thought to be a decisive day in that '71 Tour. But it turned into what they still say write about as one of the greatest exploits in Tour history. Having put a little time into the Cannibal in the Chartreuse the day before, Ocana knew it was a big chance. So he struck out early with Agostinho, Zoetemelk and VanImpe. Dropped them, and soloed to a massive 8'40" spanking of Eddy Merckx.
Some say Ocana would have gone on to win that Tour easily if he hadn't been so impetuous and proud as to try to match Merckx descending the Col de Mente in a slick deluge. Don't know about that, but do know (at the risk of invoking a tired stereotype I'm far from the first to cite) there was more than a little matador in Luis Ocana.
And in Alberto Contador, too.
His deft mano-a-mano capework in the arenas of Los Lagos and Cuitu Negru lulled a compact but fierce bull named Purito into a relaxed feeling of approaching, imminent victory. Then when the bull was set up, tired but maybe a little too confident and complacent, he drove the sword in to the hilt at Fuente De.