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.
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While he's mellowed somewhat over the years, particularly since he became co-owner of Stewart Haas Racing, there is no tougher or more competitive driver in Sprint Cup in our mind than Tony Stewart.
He even has an intimidating nickname of "Smoke" for the way he smokes opponents when he's at the top of his game. In addition to being tough,
Stewart is also arguably the most versatile driver in Sprint Cup, having won numerous races and championships across a number of series, including three Cup titles, an IRL crown and numerous Sprint Car, Midget and other series championships in his storied career.
One other thing: Stewart rarely backs down from a fight, especially if he feels he's right. While he's had a few run-ins over the years with media, track promoters (remember the off-season incident a couple years back in Australia that was almost an international incident) and other drivers, we like the modern-day version of Stewart: he's still tough, but at least he usually smiles when he is.
Bakersfield, Calif., native Kevin Harvick is almost as tough as Tony Stewart. He's a hard-nosed competitor who trades paint and bangs fenders with the best of them.
Harvick can have a short fuse at times, as does Stewart, but if he feels he's in the right when he was wronged by another driver or perhaps a NASCAR official, he'll make sure every camera, microphone and reporter within earshot knows it.
Like Stewart, Harvick has mellowed somewhat over the last 12 seasons, but light a fire under him and he's still as fiery as ever. It should be really interesting to see what happens when Harvick joins Stewart's team in 2014.
Okay, Jimmie Johnson is not an intimidating figure when it comes to physical size. He's also likely to walk away from a fight than take part in one.
But there's no denying the toughness within a guy who not only won one Sprint Cup championship, but then went on to win an unprecedented five titles in a row (2006-2010) to boot.
Johnson lets his talent and competitiveness do most of his talking for him on a race track. He's been accused of being too "vanilla" at times, but when a race is on the line and Johnson feels he can win it, you won't find a harder or more savvy driver.
When lurking in a rear-view mirror, Johnson puts pressure on other drivers perhaps more so than any other driver on the circuit, and finds a way to either power drive his way around opponents or causes them to make mistakes that allow the JJ Express to get by and not be denied.
After the mediocre season he had in 2012, you may wonder why we'd rank Busch so high. That's simple: 105 wins across all three of NASCAR's pro series (24 Cup wins, 51 Nationwide wins and 30 Trucks wins).
Keep repeating that mantra to yourself and you'll see why the younger Busch brother is indeed one of the toughest competitors on the Sprint Cup circuit.
While he has incredible talent, Busch also drives with a style that is like a power play in hockey: he's always attacking an opponent, looking for a hole to slide through and get by.
Earlier in his career, Busch was criticized at times for wrecking too many cars. But he's learned from those mistakes and has become one of the sport's toughest challengers.
Even if you're not a KyBusch fan, admit it, the 2012 Chase for the Sprint Cup just wasn't the same without him in it. That's the mark of a truly tough driver.
Mark Martin? Really? Yes, Martin is indeed one of the toughest drivers out there, but in a different way than guys like Kyle Busch and Tony Stewart.
Martin is an old-school racer. He races you close and clean and tight, but when he puts the pressure on you, you know you're in a true and real race...or a race within a race, for that matter.
Another element that Martin possesses is how physically fit he is. Even at 52 years old (just turned it last week), he can still drive the wheels off a race car, not to mention show up drivers half his age.
And I mean this in the most complimentary form possible: even though Martin has never won a Sprint Cup championship in his career, to finish second five different times shows the caliber and mettle he's made of. He is one tough guy you don't want to mess with.
For all the issues the elder Busch brother has had in recent years, including losing his ride at Penske Racing following a blow-up at ESPN reporter Dr. Jerry Punch, there's still no denying Busch's talent behind the wheel.
Busch is a threat to win virtually every time he puts on his firesuit. Even with a small team and minimal equipment, he still did relatively well last season during his 30-race tenure with Phoenix Racing before moving to Furniture Row Racing.
FRR is somewhat of an upgrade from the Phoenix group, so we would not be surprised to see Busch win a race or two this season. He's learned a lot of very valuable lessons and from his mistakes, which should make a tough driver even tougher going forward.
We have always considered Greg Biffle as one of the most underrated drivers on the circuit. If we had to compare him with other drivers, he'd likely be part Matt Kenseth for his relative quietness, along with part Kevin Harvick for his tough-as-nails and aggressive demeanor behind the wheel.
I guess the best way to describe "The Biff" (his nickname) is he's tough in a quiet kind of way.
Let's face it, you don't win both a Trucks and Busch (now Nationwide) championship by being a poor driver. And if he ever wins a Sprint Cup championship (which we think is still possible) Biffle would become the first driver in NASCAR history to win championships in all three professional classes.
You don't get much tougher than that.
You don't win four Cup championships in your career and not be considered a tough driver.
And while Jeff Gordon has chased title No. 5 for the last 10 seasons, he still has the ability and talent left to achieve that goal before he eventually retires from NASCAR. If you have any doubt, reflect back on the way he won the 2012 season finale at Homestead.
We wouldn't be surprised that if Gordon does win a fifth title, that he calls it quits right afterward, going out on top. That would be the perfect ending to Gordon's Hall of Fame-worthy career.
Sure, Gordon may be smallish in physical stature, but he is definitely one of the giants in NASCAR history. And when he's on his game, there are few drivers out there that are tougher to beat.
You know you've done wrong when you're called to the NASCAR hauler.
Reigning Sprint Cup champion Brad Keselowski is a tough driver, too, but not just because he won the 2012 championship.
Rather, Keselowski has had a number of run-ins with other drivers in both the Nationwide and Sprint Cup series and always held his ground.
When Carl Edwards tried several times to bait the young Keselowski a few years ago, the latter showed the former that he wasn't going to take any guff and that he wasn't going to be intimidated, even getting in Edwards' face once before the two were separated.
Keselowski is a modern-day driver that races like an old-school racer. He's definitely a throwback to the days of drivers like David Pearson. And they didn't come much tougher than Pearson.
Okay, we know your reaction? JPM is a tough driver? Really? A guy who has won only six years and seemingly continues to get worse every season?
In his own way, Montoya really is a tough driver, but not for most of the reasons we've mentioned of the top nine drivers in this list. To put it simply, JPM is the ringer of our list.
Whenever there's trouble to be found on a race track, Montoya is seemingly either involved or close by. We've lost count of the number of skirmishes he's had with other drivers. He doesn't just trade paint, he makes sure he gets through to the primer when he bangs fenders with other drivers.
There's no denying Montoya's record. Other than finishing eighth in 2009, he's finished 20th in 2007, 25th in 2008, 17th in 2010, 21st in 2011 and 22nd in 2012.
But perhaps the most telling stat is lead lap finishes. Montoya tied a Sprint Cup career low in 2012, finishing on the lead lap just 13 times, just over a third of the 36 races he started.
In addition, he had five DNFs (four due to wrecks) and came back on the track after lengthy repairs that put him several dozen laps down two other times.
Add all that up, and that's 20 of 36 races that Montoya wasn't a factor in.
And who can forget Montoya becoming the first driver in NASCAR history to total his race car and a track jet dryer at the same time (and under caution, too) at last year's Daytona 500?
Yes, Montoya definitely belongs on this list as a tough driver…or perhaps the driver with the toughest luck out there. If that were the case, he'd likely be in a category all his own.