Standing at 6-foot-4, junior middle blocker Haleigh Nelson is boisterous and energetic at every Wisconsin volleyball practice.

In the almost empty gym on weekday afternoons, she is in the middle of nearly everything the team does: yelling and pumping up teammates, cracking jokes, working hard and never shying away from plays.

But when it’s her turn to step up to the service line, a different side of Nelson can be seen.

She becomes stoic and fixated on the task at hand as she stands isolated on the stripe.

Her opponents on the other side of the net frantically try to position themselves for what is coming, flashing worried looks as Nelson delivers her serve.

A loud crack can be heard as Nelson strikes the ball. Within a second, it has already crossed the net as two of her opponents dive to receive, but it’s too late. The ball smashes off their forearms and flies into the stands, something opponents of Nelson experience far too often for their liking.

Nelson now boasts a serve that is considered by her teammates to be the best of the Badgers, but it hasn’t always been that way, as mental roadblocks have limited the serve’s progress in the past.

“The potential has always been there for me to be a good server,” Nelson said. “I was limiting myself mentally though. I was serving really well in practice and I had a lot of confidence going up against [Wisconsin’s] passers. But when it was game time, I would take some power off and I wasn’t as confident.”

That lack of confidence came from the sheer pressure of the act itself Nelson said, before even factoring in the crowd or opponents.

As many of her teammates have said, the art of serving is something intangible. It takes much more than just practice itself.

“[Serving] is just being able to go back to the service line and clear your mind,” senior libero Taylor Morey said. “Whether you’ve served one ball, five balls or 10. We work a lot on our in percentage and that’s something that I try to take pride with, that my serve is serve-confident and in the court.”

Nelson said her inexperience on the court in years past contributed to her lack of confidence and that she needed to start being able to transition her hard serve in practice over to actual games.

She worked with coaches after most players had gone home from practice, sometimes against the wishes of head coach Kelly Sheffield, and talked with more experienced players.

She even developed a new approach to her in-game methods.

“I’ve tried to be really confident this year,” Nelson said. “I made the decision earlier this year that I was going to come back [to Wisconsin] and serve with no fear and go all out every time, move the defense however I want.”

That execution, Nelson said, comes from the conscious effort to remain relaxed while at the service line and being able to handle criticism if she serves poorly.

And that progress is evident in the boxscore, as Nelson has gone from 0 aces per set her freshman year, to 0.25 aces per set in 2015 — a top 15 average in the Big Ten.

But Sheffield believes that the end-product cannot be pegged to such simple simple reasons.

“I’ve seen her become a better athlete by her hard work in the weight room and with our strength coaches,” Sheffield said. “It’s fed into her becoming a much more confident player and a leader.”

That confidence has driven Nelson to deliver 14 aces on the year so far, only four aces shy of her career high of 18 set in 2014.

Those numbers are a product of solid all-around play for the junior, who hit a game high four aces against Kent State back in September and is sporting a .947 percent serving percentage this season. Even her hitting has gotten better each successive season, having increased her kills per set by at least 20 percentage points each season.

Nelson’s confidence could be a simple decision as she’s said, evidenced by her change in attitude once she approaches the service line, or hours spent in the gym as Sheffield believes, shown in the improvements in her statistics all across the board. Teammates are indifferent as to which is truly correct, as long as Nelson continues to deliver.

“I’m glad she has the confidence in herself to go after it,” sophomore outside hitter Lauryn Gillis said. “Passing her serves in practice is very, very challenging. It’s something that’s a pain but at the same time a challenge and fun…It alleviates our defense and lets us focus on other troubles we have.”