Not only was the past season significant in the fact that the PBR celebrated its 20th anniversary, but the Built Ford Tough Series was also memorable in its own right for how it played out over the past 10 months.

In a series of “throwback” stories being posted each Thursday between now and the end of the calendar year, PBR.com will look back at some of the key moments from throughout the historical season.

The latest in the series features the matchup between Bushwacker and Pistol Robinson with $40,000 on the line during the summer break at J.W. Hart’s PBR Challenge in Decatur, Texas.

The highly-anticipated matchup arose on May 23 during a Twitter exchange between Hart and Robinson. Hart had called current riders chasing points in the world standings "spineless" for not riding some of the PBR's toughest bulls during the Built Ford Tough Series summer break. Robinson later responded, and after a series of tweets, the $40,000 bet was made – making national headlines.

Pistol Robinson put up up $1,000 and J.W. Hart gave him 40-1 odds to face off against one of the PBR’s all-time greatest bulls.

Bushwacker was still amidst his record Built Ford Tough Series buckoff streak at the time, and his streak was technically not in jeopardy because the attempt would be an exhibition.

Regardless, the eventual 2013 World Champion Bull once again showed his dominance and bucked off Robinson with ease in 3.56 seconds during the summer event.

Here is that story as it appeared on the website Saturday, June 9, 2013:

The crowd inside the Wise Country Sheriff's Posse Arena was on its feet and everyone around the arena was climbing on top of the chutes eagerly awaiting the final ride of the J.W. Hart PBR Challenge Saturday night in Decatur, Texas.

With every extra ounce of anticipation radiating throughout the arena, another hair on the back of J.W. Hart's neck would rise.

$40,000 was at stake and everyone knew it.

"It was really hair-raising. The hair on the back of my neck was standing up the whole time. There wasn't a seat empty. Nobody wanted to miss it."

However, all it took was 3.56 seconds for Bushwacker to calm Hart's nerves and bring the crowd to life as the 2011 World Champion Bull bucked off Pistol Robinson in a featured exhibition to cap off the J.W. Hart PBR Challenge.

"It was really hair-raising," Hart said. "The hair on the back of my neck was standing up the whole time. There wasn't a seat empty. Nobody wanted to miss it."

Hart is going to donate the $1,000 dollars he won from Robinson - as a result of a previous bet the two agreed to on Twitter on May 23 - to the Moore, Okla., tornado relief fund.

It was a fitting end to the 10th annual Touring Pro Division event, which was won by Jordan Hupp. The Cheyenne, Wyo., native was the only rider to conquer two bulls in Decatur and scored an 89.5 in the short round.

Hart said he could not be prouder of the effort, and fearlessness, that Robinson brought to the event.

"I just appreciate Pistol stepping up and being a cowboy," Hart said. "He put his hand in the rope and tried hard. He put the effort out there and I admire what he stands for."

Bushwacker was able to toss Robinson on his third buck after hitting a deep patch of sand on his first attempt. Robinson was able to climb back into position, but then Bushwacker did what he does best and took over the ride.

There was no official bull score because it was an exhibition ride.

"At about the second jump, he really snatched on me, and my whole game plan was to try and stay small," Robinson said. "I tried crawling back out and I got back out over him, and the next jump my feet clicked and that was it.

"He got my feet and I'm another statistic in his book."

Robinson was also proud to be a part of an event that featured a special ceremony when Hart and his event committee donated five mortgage-free homes to wounded veterans through the Military Warriors Support Foundation.

Bushwacker's record buckoff streak of 42 straight on the Built Ford Tough Series was technically not in jeopardy, as Saturday's event was a non-BFTS event. However, including TPD events, Bushwacker has now bucked off 56 consecutive riders.

Still, hauler Kent Cox said he could sense the importance of Saturday's Bushwacker-Robinson showdown. The anticipation leading up to this matchup garnered national attention and Bushwacker rose to the challenge like he is accustomed too.

"You can definitely feel the energy in the crowd today and he had to of felt it, as well," Cox said. "You can definitely tell everybody was watching this deal. They came to see this."

Oh, and Cox thinks Hart should have a new best friend.

"I don't know if J.W. has anything planned or not, but (Bushwacker) definitely ought to be his best friend right now," Cox laughed.

Cox also added it was good to give Bushwacker some action during the current summer break from the BFTS. As of now, Bushwacker is next scheduled to return to action on Aug. 16 at the BFTS event in Tulsa, Okla. However, things can always change.

"You can't just lay them bulls up all summer long and expect them to buck come time for Tulsa," Cox said. "We are always looking for a few places to buck them during the summer just to keep them somewhat tuned up."

Bushwacker certainly appeared to be in sync, taking down Robinson once the ferocious animal athlete found his footing. The Burleson, Texas, native said he has ridden stronger bulls before, but it's Bushwacker's bucking ability that makes him so successful.

"He is not a treacherous or scary bull. He is a rank one," Robinson said. "Every bull rider wants to conquer him and I was just trying to be cool and get it done.

"He is a different kind of bull. He doesn't feel strong. He doesn't feel dirty. He just bucks."

The highly-anticipated matchup between Bushwacker and Robinson arose on May 23 during a Twitter exchange between Hart and Robinson. Hart had called current riders chasing points in the world standings "spineless" for not riding some of the PBR's toughest bulls during the BFTS summer break. Robinson later responded, and after a series of tweets, the $40,000 bet was made.

Robinson was willing to put up $1,000 against Hart's 40-1 odds that Robinson could successfully ride Bushwacker for 8 seconds.

Although he failed to conquer the World Champion Bull, Robinson does not regret taking on Hart and Bushwacker.

"Money comes and goes," Robinson said. "Absolutely not one regret. I wanted to ride him just to say I was the first one to get it done. It's pretty disappointing because I was pretty sure I could get it done tonight." 

Robinson says he is still confident about taking on the PBR's prized bull and hopes their paths will across again in the future.

"I look forward to getting on him again," he said. "Maybe it won't be such a grudge match the next time I get on him between me and J.W. But you never know."

Follow Justin Felisko on Twitter @jfelisko.