When you refer to someone in racing as "tough," it can mean a number of things from being physically challenging size-wise to having an intimidating demeanor behind the wheel.
It can also mean being one of the hardest driving competitors on a race track to being a competitor who may not necessarily be the best driver out there, but who presents a challenge by the way he drives, particularly those who border on the haphazard.
We looked at all full-time drivers on the Sprint Cup circuit and, after mulling over their careers and the type of drivers they are as well as some of the conflicts they've had on- and off-track, came up with who we feel are the 10 toughest drivers in the sport.
Feel free to disagree or add your own pick in the comments section.
Follow me on Twitter @JerryBonkowski. Also, catch me this Sunday (Jan. 20) from Noon until 3 pm ET on "The Back Stretch" on SiriusXM NASCAR Radio, Channel 90.