The transformation occurred quickly, Kem says. In the Arizona tournament, they were monomaniacally focused on baseball. In California, they began noticing girls were wearing bathing suits in the pool. By Williamsport, they were telling the coaches they were going to watch other games when, in fact, they were walking around "being seen."
"It's been amazing watching the hormones kick in over the last year," Kem says. "With that, you get the attitude and the language. It creates all new challenges as a parent and a coach."
The success of the Chandler National team is more a product of Arizona's burgeoning club ball scene than anything else. In fact, most of last year's team had spent the years before honing their skills on year-round competitive teams. A month before Chandler National made its run, many of the team's players were in Cooperstown, New York, winning a major national tournament as members of the Chandler Express club team.
Many of the All-Stars spent the last year playing for the club team Kem helps coach, the Chandler Monsoon, which also includes three top players from the northwest Valley. The Monsoon, which recently beat California's top 13U club team and has lost only a few times in more than 90 games, is arguably the best 13U club team in the western United States.
The Monsoon would very likely trounce the Chandler National All-Star team, if such a game were possible.
And that's pretty typical. The best club teams in Arizona are generally a step ahead of the state's best Little League all-star teams.
But that gap is closing, primarily because it is once again cool for club ball kids to play Little League in the spring.
In the East Valley, participation in recreational baseball leagues such as Little League, Matt Williams and Chandler Youth Baseball is up about 30 percent.
Most of the top club ball interest, though, is focused on the top division of Little League. That's where the All-Stars come from. That's where the most public and media interest in youth baseball is focused.
In this year's Chandler National Little League, for example, players from nine different top club teams have interrupted their club ball schedule to play in the league's Majors Division.
Most of the league's coaches also have coached club ball teams.
Many of the club players in CNLL continue to play with their club teams every other weekend at the same fields in an East Valley club league sponsored by Klimchock and the Major League Alumni Association.
The same migration from club ball to Little League is happening in other Valley cities, including Ahwatukee, Scottsdale and Glendale.
And after Little League, most players will return to their club teams, playing in relative obscurity as they hone their skills for the next levels.
For last year's Chandler All-Stars, their club ball schedule is preparation for junior high ball, which, in their case, is hopefully preparation for playing at Hamilton High School, which won last year's state 5A baseball championship; then college ball at ASU (where Barry Bonds played, incidentally), Grand Canyon University or any one of the area's two-year colleges, all of which regularly produce major league draft picks.
"These kids are now pretty much focused on the things they need to do to be able to play high school ball," Kem says. "These kids love baseball and are so immersed in the sport that they know the skills they need to pick up to play at the next level. There's a focus and an understanding of the game that we just never had as kids this age. It's really amazing to watch."
The ESPN commentators during last year's Little League World Series several times commented that the Chandler team was one of the most fundamentally sound teams they had seen in the tournament. They weren't weirdly big like many of the teams. They just made all the plays they needed to make.
"You're just seeing that level of play here at that age," Kem says. "With all the club ball and good coaching around, you've now got kids running around with the skills of good high school players. It's just a different world."
It is the night before New Year's Eve in the desert north of Phoenix. This night will end up killing many of the ficus trees in the Valley. The ficuses can handle the heat, but they can't handle a freeze.
It is the first round of the Super Series Winter Nationals baseball tournament here at the Victory Lane Sports Complex.
The players for the McDowell Mountain Yankees 11-and-under team huddle in the dugout around two propane heaters, rubbing their hands and rolling their bats near the heater's orange flame like hot dogs over a campfire. Aerospace-grade double-wall aluminum can handle high temperatures, but it loses its pop at below 60 degrees.