Dirt racing is what defines Tony Stewart

— -- Many folks who don't consume motorsports have asked me in recent days why Tony Stewart would compete at nowhere tracks, for no money, with so much risk. The best analogy I could muster was Kevin Durant at Rucker Park.

When Durant showed up at Rucker last summer and dropped 66 on the boys at the playground, everyone gushed about how cool and genuine it was that he went back to the roots, and paid homage to the purest form of the game. No money. Just ballin'.

Sure, there was considerable risk involved. One wrong movement could result in a career-ending injury. That's part of the respect that comes with his appearance there. Risk it for the game, baby. Use your celebrity to pay the game back for all it has done. And since nothing happened to Durant outside a jaw-dropping display of his MVP skill, we found it fascinating and wonderful that he did it.

That's what Stewart does every weekend. Same premise. It's passion. It's a reset button, a reminder why he does what he does and is who he is. It's a body-cleanse from the corporate toxins that affect the NASCAR owner.

And now that passion is under fire again. It was under fire last year at this time, after Stewart shattered his right leg in a crash at Southern Iowa Speedway. When he wrecked in that sprint car race last August, he swerved left to avoid hitting Josh Higday in the driver's door. I visited Higday three weeks ago in Des Moines, and he told me that Stewart's split-second decision saved Higday's life. He told me there are only a handful of drivers on earth that had the ability to make that move.

Flash forward to Saturday night: Stewart struck Kevin Ward Jr. during a sprint car race at Canandaigua Motorsports Park. Ward died as a result, an unspeakable tragedy that left the entire motorsports community in shock, and prompted news outlets to study racing safety and question Stewart's actions and comment on his temper and ponder why he runs these races anyway.

He runs them because he needs them. Certain things define certain men. The dirt defines Stewart. On dirt, in his mind, he's just a guy. It's pure. It's real. It's honest. That's why Stewart needs the dirt. Right there.