Everyone in the gym could see it coming.

As Columbia senior Jeff Coby’s three rattled through the net—completing the Lions’ comeback from a 17-point halftime deficit—junior co-captain Siyani Chambers began motioning for the inbound. Harvard coach Tommy Amaker lets his players play through these situations, trying to catch the defense before it’s set; his floor general was ready to go.

Chambers brought the ball up, scarcely looking at trailing senior wing Wesley Saunders. By the time he started his drive, Saunders was still ambling up the right side—sliding into position for the dribble handoff play Harvard ran in similar situations against UMass and Brown.

Columbia point guard Maodo Lo picked Chambers up, shading over to make the left-handed Cham   bers finish with his right. Then came the hesitation dribble, a quick bit of separation and the flick. The ball splashed through the net for the ensuing game winner, and Crimson fans heaved a sigh of relief.

As the Ivy League race barrels to a head, Chambers remains the most intriguing part of the whole puzzle. He is not the league’s best player—heck, his coach readily gives the “team’s best player” title to backcourt mate Saunders. Assessing his play—and value to the team—is complicated.

After Amaker stressed before the season his goal for Chambers to improve his decision-making and shot selection, the junior’s shooting marks are down across the board for a second-straight year. His turnover ratio is nearly 21 percent, and he has a rock-bottom 42.5 percent effective field goal percentage.

But what he can give you is harder to measure. Since arriving on campus, he’s been the team’s primary ball handler and an on-court presence; elected a captain after his sophomore year, Amaker noted Wednesday that the team’s youngest rotation player has become its vocal leader. On a team struggling for offense, Chambers sprints on every rebound—creating as many “secondary break” opportunities as possible, looking for easy points on every drive.

His defense has improved drastically since his freshman year, with his defensive rating dropping nearly 10 points. By any measure, he’s the team’s best clutch player. Chambers has shot eight-of-13 in the final two minutes of single-possession games in his career, leaving a litany of opponents empty-handed.

Freshman year it was BU, driving right and creating space for a step-back jumper as time expired. Sophomore year was Cincinnati, when Chambers nailed a crucial jumper late to clinch the victory. In December, he nailed a three at the end of regulation to send his team into overtime against Vermont.

After the Vermont jumper, Chambers turned to his bench. The most effusive Crimson player was stoic, staring down his teammates with unbridled satisfaction and a touch of smugness. The point guard carries himself with the cocksureness of someone who’s won everywhere he’s gone.

It’s not misplaced.

The junior is a staggering 54-20 in his career at Harvard. He made his high school varsity team in eighth grade, teaming up with Royce White as a freshman to take home his first state title. When White left, little changed—Chambers made it a trifecta of state championships. His senior year, he averaged 30 points a game in single-handedly willing his team to third place.

His freshman year, he led all Division I freshmen with 5.7 assists a game—taking on a leadership position as, in the wake of the withdrawal of two of its best players, the team coalesced around him. Shooting 42 percent from three, he and Saunders were the league’s best backcourt. Then-senior Christian Webster ’13 noted, “Laurent [Rivard ’14] and I are the captains, but he’s the leader.”

In many ways, this Crimson team has deeper shades of 2012 than 2013. Harvard hasn’t blown out opponents as it did last year, giving away double-digit leads in half of its league games. Chambers noted Wednesday with more than a hint of disgust that the team has struggled to finish games.

As the team kicks off its stretch run this weekend—Saturday starts a stretch of four straight games against the rest of the league’s top five—no player will be more important to its success. And when it comes time to finish, the ball will be in his hands.