What made Ernie Banks great?

Ernie Banks hit 512 home runs during his 19-year career. Banks became known as much for his optimism and love of the game as his home runs and back-to-back National League MVPs.

Even as the Chicago Cubs lost one game after another, Ernie Banks never lost hope.

That was the charm of "Mr. Cub."

Banks, the Hall of Fame slugger and two-time MVP who always maintained his boundless enthusiasm for baseball despite decades of playing on miserable teams, died Friday night. He was 83.

The Cubs announced Banks' death, but did not provide a cause.

Banks hit 512 home runs during his 19-year career and was fond of saying, "It's a great day for baseball. Let's play two." In fact, that sunny finish to his famous catchphrase adorns his statue outside Wrigley Field.

And on a cold winter night Friday in Chicago, the ballpark marquee carried the sad news for the entire town to see: Ernie Banks. "Mr. Cub." 1931-2015.

"Words cannot express how important Ernie Banks will always be to the Chicago Cubs, the city of Chicago and Major League Baseball. He was one of the greatest players of all time," Cubs chairman Tom Ricketts said in a statement. "He was a pioneer in the major leagues. And more importantly, he was the warmest and most sincere person I've ever known."

"Approachable, ever optimistic and kind hearted, Ernie Banks is and always will be Mr. Cub. My family and I grieve the loss of such a great and good-hearted man, but we look forward to celebrating Ernie's life in the days ahead."

In a statement Saturday, President Barack Obama and first lady Michelle Obama expressed their condolences "to the family of Ernie Banks, and to every Chicagoan and baseball fan who loved him." The president said Banks became known as much for his optimism and love of the game as his home runs and back-to-back National League MVPs.

"As a Hall-of-Famer, Ernie was an incredible ambassador for baseball, and for the city of Chicago," President Obama said. "He was beloved by baseball fans everywhere, including Michelle, who, when she was a girl, used to sit with her dad and watch him play on TV. And in 2013, it was my honor to present Ernie with the Presidential Medal of Freedom.

"Somewhere, the sun is shining, the air is fresh, his team's behind him, and Mr. Class — "Mr. Cub" — is ready to play two."

Though he was an 11-time All-Star from 1953-71, Banks never reached the postseason. The Cubs, who haven't won the World Series since 1908, finished below .500 in all but six of his seasons and remain without a pennant since 1945.

Still, he was inducted into the Hall of Fame in 1977, the first year he was eligible, and was selected to baseball's All-Century team in 1999.

Banks' infectious smile and non-stop good humor despite his team's dismal record endeared him to Chicago fans, who voted him the best player in franchise history. One famous admirer, actor Bill Murray, named his son Homer Banks Murray.

In 2013, Banks was presented with the Presidential Medal of Freedom — by a noted Chicago White Sox fan, President Barack Obama. The award is one of the nation's highest civilian honors.

"Ernie Banks was more than a baseball player. He was one of Chicago's greatest ambassadors. He loved this city as much as he loved — and lived for — the game of baseball," Chicago Mayor Rahm Emanuel said. "This year, during every Cubs game, you can bet that No. 14 will be watching over his team. And if we're lucky, it'll be a beautiful day for not just one ballgame, but two."

Banks' No. 14 was the first number retired by the Cubs, and it hangs on a flag from the left-field foul pole at the old ballpark.

"I'd like to get to the last game of the World Series at Wrigley Field and hit three homers," he once said. "That was what I always wanted to do."

But even without an opportunity to play on the October stage, Banks left an indelible mark that still resonates with fans and athletes from all sports.

"Ernie Banks... We are going to all miss you. #Legend," quarterback Russell Wilson tweeted as he and the Seattle Seahawks were getting ready to defend their Super Bowl title.

Banks was playing for the Kansas City Monarchs of the Negro Leagues when the Cubs discovered him in 1953, and purchased his contract for $10,000. He made his major league debut at shortstop on Sept. 17 that year, and three days later hit his first home run.

Tall and thin, Banks didn't look like a typical power hitter. He looked even less so as he stood at the plate, holding his bat high and wiggling it as he waited for pitches. But he had strong wrists and a smooth, quick stroke, and he made hitting balls out of the park look effortless.

When he switched to a lighter bat before the 1955 season, his power quickly became apparent. He hit 44 homers that season, including three against the Pittsburgh Pirates on Aug. 4. His five grand slams that year established a major league record that stood for more than 30 years before Don Mattingly hit six in 1987.

Banks' best season came in 1958, when he hit .313 with 47 homers and 129 RBIs. Though the Cubs went 72-82 and finished sixth in the National League, Banks edged Willie Mays and Hank Aaron for his first MVP award. He was the first player from a losing team to win the NL MVP.

Banks won the MVP again in 1959, becoming the first NL player to win it in consecutive years, even though the Cubs had another dismal year. Banks batted .304 with 45 homers and a league-leading 143 RBIs.

He led the NL in homers again in 1960 with 41, his fourth straight season with 40 or more. His 248 homers from 1955-60 were the most in the majors, topping even Aaron and Mays.

"Mr Cub. What you have done for the game of baseball the city of Chicago and everyone you have ever touched will never be forgotten. RIP," tweeted Cubs first baseman Anthony Rizzo.

Though Banks didn't break the 40-homer barrier again after 1960, he topped the 100-RBI mark three more times, including 1969, his last full season. Then 38, he hit .253 with 23 home runs and 106 RBIs, and was chosen an All-Star for an 11th time.

On May 12, 1970, he hit his 500th home run at Wrigley Field, becoming only the eighth player at the time to reach the plateau.

Banks retired after the 1971 season. He owned most of the Cubs' career slugging records, some of which still stand today.

Known mostly for his power at the plate, Banks was a solid fielder, too. He is best known as a shortstop, where he won a Gold Glove in 1960, but he switched to first base in 1962. He played 1,259 games at first and 1,125 games at shortstop.

Born and raised in Dallas, Banks would be bribed to play catch by his father, who always wanted him to be a baseball player. Banks grew to love the game and was a standout in high school, along with participating in football, basketball and track and field.

He joined a barnstorming Negro Leagues team at 17 and was spotted by Cool Papa Bell, who signed him to the Monarchs in 1950. Banks played one season before going into the Army. He returned to Kansas City after he was discharged, playing one more season before joining the Cubs.

"He was one of the great crossover baseball players of his day," the Rev. Jesse Jackson said. "His personality was a racial bridge builder. He treated all people with dignity and respect. He never stopped reaching out to bridge the racial chasms."

Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.