Professional sports can become so pressured that it can sometimes be on the precipice of letting the simple pleasures pass it by, unless you're Imran Tahir. Then, the game is all about those things.

The legspinner bowls every ball with the effort he would put into the last ball he will ever bowl, and no matter what the outcome, he has a reaction.

If he is hit for runs - even a run - it is the worst run that has ever been taken off him. He puts his hands on his heads or his hips, chews his lip nervously or shakes his head in irritation. If he beats the bat or induces a miscued or mis-timed shot, when the batsmen fail to pick him properly, he reacts as though he has committed the ultimate act of deception. His face contorts into an expression of regret: if only he'd gotten away with a wicket. If he senses there is an appeal to be made, he makes it as though it is the last time his voice will be heard. He stretches his arms out, arches his back and belts it out, even if there is no choir to join his chorus. If the appeal is successful, the real fun begins.

Tahir has been known to take off with such gusto the security officials aren't quite sure if they should follow him lest the spectators need protection. Sometimes his team-mates follow. Other times, they wait for him to come back. He always does.

That's the thing about Tahir. No matter how bad it has got, or how many times his career has been on the cusp on ending, he has come back. "I just like challenges," he said. "I had a lot of them in my life, and then when it comes to that, I think I can be ready for anything, really."

Over the last 12 months, he has come back to carve a niche for himself as South Africa's premier limited-overs spinner. Perhaps that was what Tahir was always meant to be.

Although he was initially selected to be part of a Test squad - to play England in January 2010 before he was properly eligible to represent the country - he made his debut as an ODI player. At the 2011 World Cup, Tahir was South Africa's second-highest wicket-taker after Robin Peterson and had featured in two fewer matches, but he was left out of future fifty-over squads until late 2013 and has been a fixture ever since.

Unlike in the longer format, when his variations have seemed to confuse him more than the batsmen he is bowling to, Tahir has control in limited overs and he first showed it in the shortest format. He played in seven T20s before last year's World T20, where he began to refine his strategies for limited-overs cricket.

"The last T20 World Cup we played in Bangladesh I started talking a lot to AB (de Villiers) Faf (du Plessis) and Hashim (Amla) and I think that helped me a lot," Tahir said. "If I could bowl to those guys I know I can bowl to anyone in world cricket."

That was also when Tahir put in extra hours on the other aspects of his game - batting, fielding, fitness and more discerning analysis. Prasanna Agoram, South Africa's video and statistical guru has been "helping me a lot, telling me about my feel, what to do and stuff," Tahir said. "These are the few things which are small, but that improves my game, and that's what I think is the reason I've been so consistent."

The most impressive aspect of Tahir's game has been ability to control the middle overs by restricting batsmen and plucking wickets. His ODI economy rate is 4.38 runs to the over and 4.30 in this tournament, numbers which appear more startling because of the regularity with which totals of 300 are chalked up. Tahir bowls a teasing line and length which is difficult to get away with and has gone wicket-less only three times in 33 ODIs.

Recently, he has been taking more wickets as batsmen try to take him on but fall on their sword. And the more wickets he has taken, the more he has enjoyed himself, the better his contributions have become and the more confidence he has gained.

"I'm just really honoured to play for South Africa. Just to be part of this team is a special feeling," Tahir said. "I think about that when I walk onto the field. I think about all the good people in my life who helped me in my career. My wife, my kid are here. I think that's made my arms a little bit stronger - carrying him for a few nights. With their support and with my team's support, I'm just really glad and very happy to be where I am today. When you always walk into the middle with green and gold, I just want to take 10 wickets every game."

Imagine the fun if that happens.

Firdose Moonda is ESPNcricinfo's South Africa correspondent