Or what if Grubb had decided not to give it his all those final weeks since he knew he wouldn't be returning to Stewart-Haas Racing?
Would Stewart still have won the NASCAR Sprint Cup title? Would Carl Edwards be the defending champion? Would Grubb be where he is now, back in the title hunt?
Denny Hamlin's win Sunday at New Hampshire continued Grubb's remarkable run. He's won six of the last 12 Chase races -- a feat Chad Knaus has done twice -- and 10 of the last 38 Cup races.
Grubb has been to Victory Lane more times than any other Cup driver or crew chief and has made two more visits than all of owner Rick Hendrick's teams have in the same period.
Grubb's greatest accomplishment, though, could come this week at Dover, if he can help Hamlin succeed at his worst track in the Chase and remain near the top of the point standings. Hamlin heads into the weekend third in the standings, seven points behind series leader Jimmie Johnson.
It's quite a way from last October when Grubb was told there was no longer a place for him with Stewart's organization.
"We needed a change [in 2011],'' Stewart recently said. "It's hard for everybody to understand because there's more to it than face value. There were other things that were involved in it that went into the decision of making a change at the end of the year.''
Instead of pouting, Grubb focused on the team and won a championship. Had he walked away, he wouldn't have that championship under his belt. He would have still found a job in NASCAR, but would he have found the one he has now as Hamlin's crew chief?
"I knew when they signed him up with Denny that it was going to be a good pairing,'' Stewart said. "I just think their approaches are very similar. Darian is a very technical guy and Denny is very technical when it comes to his car.''
Although Stewart's decision to release Grubb helped bring Grubb and Hamlin together, Stewart says he can't worry about being beaten by his former crew chief.
"You obviously know that if you make a change like that, that guy can go out and beat you, but ... you've got to do what you think as an owner to try to give yourself the best opportunity to have success,'' said Stewart, who is fourth in the standings, three points behind Hamlin.
Before Hamlin and Grubb could work together, Hamlin needed a bit of convincing this pairing would work. It didn't take long.
"My question to him was is the motivation still there to win another championship,'' Hamlin said of a meeting with Grubb last year. "[Grubb had] just won it and a lot of times that takes your motivation away. He assured me that he wanted to win one with me as bad as anything to show the outside world what he was capable of.''
That's how Hamlin feels. He wants to erase the memories of 2010, when he became the first driver in the Chase era to lose the points lead in the season finale, at Homestead.
Hamlin says his statistics show he's a top-caliber driver -- his 22 career Cup victories tie him with two-time champion Terry Labonte and former champion Matt Kenseth on the all-time list -- but he knows without that crown he won't be looked upon as equals with such drivers. That's why working with Grubb is important to Hamlin.
"When he chose me as his driver of all the people that were looking to hire him, I felt like that gave me the confidence that I was a championship-caliber driver,'' Hamlin said.
It took them only two races together to win for the first time, when Hamlin was victorious at Phoenix, a track that played a key role in losing the 2010 championship to Johnson.
"After we won the race there at Phoenix, we thought, 'Man, we are going to be pretty stout,'" Grubb said. "And since then we have been making things better and making the cars better and his feedback has been getting better and better about what we are doing. So, hopefully we can take all those things and just keep getting better and not slow down."
They have. Hamlin credited Grubb with the setup that allowed him to win at Bristol, starting a stretch where Hamlin has won three of the last five races. Hamlin led the most laps at Richmond but rain altered that race or he and Grubb would have won four of the last five races.
Hamlin was so confident about returning to New Hampshire after nearly winning there in July that he stated on Twitter he would win. He later backed off his boast when asked about it two days before the race. He shouldn't have. He led 193 of 300 laps to earn his series-high fifth win of the year.
Now comes Hamlin's biggest challenge. He has two top-10 finishes in his last 10 starts at Dover. Johnson has won four of the last seven races there. The key for Hamlin could be to limit how many points he loses to Johnson at Dover.
"I can pump myself and beat my chest all I want going into a race track, but when you haven't had success there that means you don't know what feel you are looking for,'' Hamlin said. "The good news is we're going there with a complete new package that Darian thinks will make me more comfortable and we'll see how it goes.''
It could be quite a ride for Hamlin.
"Darian has just taken this program to that next level, and obviously anyone can go on a 10-race run,'' Hamlin said. "He did it last year, and hopefully he's got some of the magic saved up for us here in the next few weeks.''