Rockville-Montgomery Swim Club Coach David Kraft did not want to appear cocky, but he couldn’t help himself. Before the start of the Potomac Valley Swimming Junior Olympic Championships in March, someone asked Kraft whether he thought his top swimmer, Jack Conger, 14, would break the national age-group record in the 200-yard backstroke.
“I know he is” going to do it, Kraft, 33, recalled saying. “There is not a doubt in my mind … And he’s going to get it by a lot.”
Conger, then a 6-foot, 2-inch eighth grader, proceeded to obliterate the previous mark by more than two seconds with his finish in 1 minute 46.82 seconds. Though he was pleased and proud, Kraft could not pretend to be surprised. In his 14th season at RMSC, Kraft feels supremely confident about two things: His swimmers, and his math.
Kraft, an A.P. calculus teacher at Magruder High in Rockville, brings the classroom onto the pool deck as a matter of course. Swimming, he believes, flows as beautifully and logically as a flawless mathematical proof. Kraft knew how fast Conger would go because he relies on various numerical formulas which he developed to turn weeks of timed practice sets into remarkably accurate race-day projections.
He uses those numbers to guide and motivate his swimmers, and to let them — and himself — know just how fast they can go. Everyone who swims for Kraft grows accustomed to poring over personal spread sheets and talking about “base times,” the magic number Kraft calculates for each, and which is used for performance projections.
“To me, swimming is so great in terms of the math,” he said by phone during a break in classes Tuesday. “You could be the greatest athlete in football or basketball, be the guy to catch the game-winning touchdown or make the game-winning shot – and never get the ball.
“That’s why I love [swimming]. So much more than in other sports, you know if you put in this work, you will get out this result.”
Plenty of Kraft’s 10-14 year-old swimmers in last year’s RMSC’s National Developmental Group in Olney put in the work and got results — extremely impressive ones. Caroline Clark, Megan Conrad, Conger, Anna Kolanowski, and Catherine Mulquin qualified for the short-course yards sectional meet last March, and Clark, Conger, Kolanowski and Mulquin claimed national age-group top-10 rankings. Conger holds dozens of records from the local to national level.
Recently, however, it was Kraft’s turn. Potomac Valley Swimming honored Kraft as its Age Group Coach of the Year, an honor he also received in 2005 when he coached Brady Fox (University of Virginia), Blair Webb (University of Pennsylvania), Zach Wepasnick (Louisiana State University) and Katie Murray (Boston College).
“He’s pretty mathematical … [and] he knows his swimmers,” said Jordan Martinko, 14, a former Kraft swimmer who was promoted to an older age-group this fall. “He knows the times they should be going in meets and, after meets, he knows exactly what to tell them. He knows everyone like they’re his little children.”
Kraft, 33, grew up in Silver Spring and learned the sport at RMSC, but he says he wasn’t nearly as good as the swimmers he now coaches. He is convinced he won a place on the swim team at Division III Washington College in Chestertown only because he worked hard.
“When I was swimming at RMSC, I was not a high-level guy,” he said. “I didn’t even know about the stuff I am now doing at 13 years old.”
He began coaching at RMSC after college and described Sue Chen, who coaches the National Training Group (elite high school kids) at RMSC’s Olney location, as a huge influence.
“We have worked hard together to help create this great program,” Kraft said.
Kraft claimed the first PVS age-group coaches award four years ago. Curl-Burke Coach Marilyn Mangels won it the next year, but RSMC coaches have won it in the years since. Kent Williams claimed the prize in 2007 and Dave Greene in 2008.
Despite all those positive numbers for RMSC, it’s not entirely about math.
“It is also really a whole lot of life skills,” Kraft said. “I talk to these kids about showing up, giving their best effort, being a leader, competing with a team. And these kids turn out great. That’s what’s nice.”