Nicky Hayden is a MotoGP world champion, WorldSBK race winner, AMA Superbike champion and one of the world's most renowned racers.
Yet he still casts an eye back to one of the few remaining accolades missing from the start of his career, a 'Grand Slam' in Flat Track.
In what might have been a first step towards completing that puzzle, Hayden was ready to get back into dirt track competition at this weekend's Superprestigio event in Barcelona, taking on the likes of Marc Marquez and Brad Baker in what would have been a mouth-watering contest.
Unfortunately, a knee injury while training in Spain last month scuppered his plans, but it proved that Hayden's dirt track desire still burns strongly.
The Kentucky Kid was a dirt track phenom in his homeland before following in the footsteps of Kenny Roberts Sr, Freddie Spencer, Eddie Lawson, Wayne Rainey, Kevin Schwantz and Kenny Roberts Jr by becoming a road racing world champion.
Having turned professional at 16, Hayden quickly established his Flat Track credentials and picked up his first race win in his second season. That success came on a Half Mile track in Maryland and from that point on he was a constant threat to win races.
During Hayden's Flat Track career his success in road racing did not count towards the AMA Grand National Championship - unlike when Roberts Sr won his titles in '74 and '75 - but his reputation grew as he added AMA Supersport and Superbike titles to his CV.
Having won on Half Miles, Short Tracks, TT (events with right hand corners and jumps) and on road courses, Hayden stood on the verge of the career 'Grand Slam'. All that stood in the way was a victory on one of the fabled Mile ovals. He came close in 2002, but then departed for Europe and MotoGP.
It's stuck in his craw ever since, while the Flat Track itch has grown so strong that Hayden needs to scratch it.
Speaking from Kentucky, Hayden said, “Last winter I was able to do some days training with [AMA Flat Track champions] Baker and Mees and they were very fast, but all I'll say is that I was very happy with how I stacked up against them.
"That probably made the dirt track itch even stronger to scratch for me again! I still love dirt track racing and if I wasn't injured I'd be riding this weekend in Barcelona. I was excited to go and compete over there.”
The draw of competing in the US is also something that Hayden refused to rule out for the future.
“I'm not sure and I've learned never to really rule out anything! If the right opportunity at the right time and place came up I'd think about it, but in all seriousness I'm concentrating on WorldSBK and there's a lot of changes in the championship next year also.”
The right time and place would lead to an attempt at joining Dick Mann, Kenny Roberts Sr., Bubba Shobert, and Doug Chandler in the Grand Slam Club.
But finding the time during a WorldSBK season, where Honda will have an all-new Fireblade this year, combined with changes to the American Flat Track Series means it's unlikely we'll see Hayden racing Flat Track on US soil in the near future.
With WorldSBK his focus for 2017 it'll be some time before the right opportunity opens for Hayden to potentially complete the Grand Slam, but the fact he's even considering it shows once again that the #69 is never a rider to be underestimated.