The Chicago Cubs started out the season as the hottest team in baseball, and although they've stumbled mightily down the stretch, they still maintain a solid lead in the National League Central Division through the All-Star break.

That success has come largely on the shoulders of five key players, and with the second half of the season set to get underway on Friday, we’re taking a look back to see which player was the Cubs’ Most Valuable Player during the first half of the 2016 season.

Kris Bryant

Bryant, one of the most highly touted Cubs prospects in history, has done nothing to dispel the hype that has surrounded him throughout his career.

This season, Bryant currently has the best Wins Above Replacement (WAR) among position players in the National League, leads the senior circuit in home runs with 25, and is in third place in the league with 65 RBI in the first half of the campaign.

Add to that his positional versatility as the Cubs have dealt with injuries, as well as his ability to hit anywhere in the lineup, and Bryant is not only a candidate to be the Cubs' MVP, but he’s a strong candidate for National League MVP honors as well.

Dexter Fowler

Although he was injured through much of the Cubs’ swoon, Fowler has been an invaluable member of the team both offensively and defensively this season.

Batting in the lead-off spot for the Cubs, Fowler has slugged seven home runs, racked up an impressive .398 on-base percentage, and has accumulated 115 total bases for the one of the best offenses in baseball. He was also voted to his first All-Star Game, one of five Cubs to receive that honor.

In the 22 games that Fowler has missed, the Cubs have gone 7-15 and have seen their Central Division lead shrink to just seven and a half games over the St. Louis Cardinals. The outfielder is expected back once the All-Star break is over, and that will be welcome news for a lineup that desperately needs his stabilizing presence.

Jon Lester

While Jake Arrieta has been struggling to find the command that made him such a dominating mound presence in 2015, Lester has picked up the slack and has (apart from his last two starts) been arguably the best pitcher on the Cubs staff this season.

Lester has 14 quality starts in 18 outings so far this season, with a 3.01 ERA and he’s averaging nearly a strikeout per inning. His WAR of 1.9 does trail Arrieta’s 2.7, but he has largely kept the Cubs in games and has been arguably the most consistent pitcher on a staff that has ranked among the league's best all season long.

The one knock on Lester is his penchant for giving up home runs. He’s given up 16 home runs in 110 innings of work so far this season, and although he's only given up 37 earned runs, he’ll need to work on keeping the ball in the park through the rest of the summer.

Anthony Rizzo

While Bryant leads the Cubs in both home runs and RBI, Rizzo has the best batting average on the team at 2.99, and he also has a team-best .416 on-base percentage in 85 games played so far this season.

Not only does the Cubs’ first baseman hit the ball with power and get on base at a higher clip than anyone else on the roster, he’s also one of the steadiest defensive first basemen in the league, and would likely be a serious Gold Glove contender if not for the reputation that Arizona’s Paul Goldschmidt has earned with the Diamondbacks.

That being the case, Rizzo is a strong MVP contender both for the Cubs and for the National League as a whole. If he can continue to put up strong power numbers and on-base numbers, he’ll remain in those conversations and the Cubs should remain in strong contention for the best record in baseball.

Ben Zobrist

The Cubs have used guys like Bryant and Javier Baez in the super-utility role that Zobrist once manned as a member of the Tampa Bay Rays under Joe Maddon, but that doesn’t mean that the veteran second baseman has become any less useful for the North Siders.

In 83 games this season, Zobrist has a 2.7 offensive WAR, racking up a .388 on-base percentage and 13 home runs for the team thus far. He was especially hot in May, helping carry the Cubs through slumps by Jason Heyward and Miguel Montero and helping the offense to some of the best numbers in the game.

His June struggles represent a completely understandable regression to the mean, but his hot early season performance illustrated exactly what the Cubs expected when they signed him: an on-base machine that can play a solid defensive second base and occasionally hit for power.

And the Winner Is…..

If Fowler was still healthy, he would be a serious contender for the MVP honors, but since he isn’t, things essentially boil down to Bryant and Rizzo. Bryant’s power is impressive, and he’s managed to become a bit more disciplined at the plate. But thanks to an advantage in on-base percentage and his similar power numbers, we’re going to go with Rizzo.