Sunday, October 4, 2026
The Sid Jacobson Hammer U17 baseball team has established itself as a dynasty on the diamond.
Earlier this month in Pittsburgh, the team captured its second straight gold medal at the JCC Maccabi Games, extending its tournament winning streak to 13. For a program stacked with Long Island talent, the performance confirmed what many already knew — the Hammer is the team to beat.
The roster included three standout players from the Bellmore-Merrick community who made their mark in the team’s championship run. Kennedy High School’s Zach Adelstein threw a one-hitter in the gold-medal game against Greater Washington, while his classmate, designated hitter Alex Demas, powered the lineup despite an arm injury that will require Tommy John surgery. From Mepham High School, outfielder Justin Lebowitz proved to be a reliable contributor
Managed by longtime coach and Seaford native Mark Rosenman, Hammer didn’t just win — they dominated outscoring opponents 72-11 across six games, using the mercy run rule to close out five of them. Their repeat title followed last year’s triumph at Rice University in Houston, a run that cemented the program’s reputation for excellence against top-tier competition.
“Coming off of last year, they felt they were the team to beat, actually prior to the tournament,” Rosenman said. “I sent them a text message with the video of the last out of [last year’s] championship game, and told the kids that participated in last year's game to remember that feeling. Let's do everything to regain that feeling. And for the kids that weren't on the team last year to visualize what they would feel like doing that as a team again.”
The departures of key players such as Derek Yormack — another Kennedy product — and Holden Cohen, left some wondering if the program’s streak would stall. Instead, younger talent stepped forward, with Adelstein and Demas leading the charge and Lebowitz providing consistency at the plate and in the field.
“Someone had asked me if the competition was better last year than this year,” Rosenman said. “I do believe the competition was as good. I know the Greater Washington team that we beat two times within this tournament, and they were in the gold medal game. They've been very strong team year after year, and they saved their best pitcher for the gold medal game, and we knocked him out. We scored 13 runs in one inning.”
Demas, in particular, drew comparisons to Los Angeles Dodgers two-way star Shohei Ohtani. Despite being limited to designated hitter duties, he batted .500 (6-for-12) with eight RBIs, nine runs scored, and five walks. His offensive presence in the three-hole gave Hammer’s lineup a dangerous edge, even as he prepared for surgery that will likely sideline him in his final baseball season at Kennedy.
“He wasn't going be able to play the field, but he didn't want to miss the tournament, so all he did was hit,” Rosenman said. “So, it’s really a great story, the fact that he put it off because this was his last year of eligibility. He wanted to win back-to-back. And he very unselfishly put off his surgery until after the tournament, and the Tuesday we got back is when he had the surgery.”
Lebowitz also delivered in crucial moments. The Mepham outfielder hit .300 (3-for-10) while driving in seven runs, scoring eight, and drawing four walks.
After rolling through their first two opponents by a combined 27-3 margin, Hammer appeared in danger of becoming overconfident. On Aug. 5, they matched up against a mixed squad that quickly exposed the danger of looking past an opponent. Four runs crossed the plate in the top of the first inning, stunning a Hammer roster that had barely been challenged to that point.
The wake-up call came quickly. Hammer clawed back to even the score in the bottom of the inning and settled in from there. Demas drew a bases-loaded walk in the third that scored what proved to be the winning run in a slim 5-4 victory.
“I kind of felt they were getting too cocky,” Rosenman said. “I kept on explaining to them that baseball is an unforgiving sport, and just when you think you have it all figured out, something happens. I said, ‘How confident are you guys?’ and they said, ‘We're gonna run-rule this team.’ I said, ‘Listen, I don't want to do this, but if this is what you feel, go out there and show me that you can play the most complete game of the tournament.
“The first ball got hit the center field,” Rosenman continued. “The center fielder, who is a very good center fielder, broke in on the ball and it went over his head for a double. The next ball was hit and the third baseman, who never makes an error, double-clutched and didn't make the play. Next play, same thing, a ball hit that should have been a double play. And they got on the bench and I go, ‘Yeah, this is your perfect game, right?’”
Sid Jacobson recovered and defeated Fort Lauderdale 13-4 in its second game on Aug. 5 before blanking another mixed team of Midwesterners 13-0 in the semifinals the next day to advance to the gold medal game against Greater Washington, whom the Hammer beat 10-0 to open the tournament on Aug. 4.
Greater Washington started its top pitcher in Michael Newman, but Sid Jacobson knocked him out quick during a 13-run second inning. Adelstein took care of the rest and his second strikeout of the game was the final out for the gold.
“It felt really good that Mark had the confidence in me to pitch the championship game,” Adelstein said. “Going into the tournament, he knew I was going to pitch in that game if it came down to it. Once the game started, I knew I was going to have a good game. Obviously, they were a good team, but I knew we were better, especially with the offense backing me up.”
Winning a third straight tournament will pose a bigger challenge for Rosenman, who will be replacing 12 players on the roster. Anyone interested in trying out for the 2026 team can email LongIslandHammer@gmail.com for more information.
