No one loves a good debate quite like baseball fans, and with that in mind, we asked each of our beat reporters to rank the top five players by position in the history of their franchise, based on their career while playing for that club. These rankings are for fun and debate purposes only … if you don’t agree with the order, participate in the Twitter poll to vote for your favorite at this position.

Here is Ian Browne’s ranking of the Top 5 left-handed starting pitchers in Red Sox history. Next week: relief pitchers.

1. Lefty Grove, 1934-41
Key fact: His 44.9 bWAR is best for a Red Sox lefty

Fittingly, the best Red Sox lefty of all-time is a Hall of Famer who answered to the name of … Lefty. Grove peaked during his nine-year run with the Philadelphia Athletics, but he still had plenty left in the tank for the final eight years of his career with Boston.

• Red Sox Top 5: C | 1B | 2B | 3B | SS | LF | CF | RF | DH | RH SP

Grove led the American League in ERA four times for the Red Sox. He also had the best ERA+ of any AL pitcher in those four seasons. In all, Grove won nine ERA titles in his career. He won 20 games in 1935 while leading the league in FIP and WHIP. The Hall of Famer was much more of a strikeout pitcher in Philly. By the time he arrived in Boston, he used craftiness to his advantage. Grove ranks 15th all-time in winning percentage and 10th in innings in franchise history.

Though he didn’t get to play on any World Series teams for the Red Sox, he was a big reason the Athletics won it all in 1929 and ’30.

2. Jon Lester, 2006-14
Key fact: Tied with Pedro Martinez and Curt Schilling with most postseason wins for the Red Sox (6)

If the Red Sox could have done it all over again, they would have made sure Lester never pitched in another uniform. Owner John Henry has admitted how badly the club miscalculated the situation when Lester had already said he would forego free agency and sign a hometown discount deal. That is all water under the bridge now, and Lester still goes down as one of the best southpaws to pitch for Boston, not to mention one of its most clutch starters ever.

Drafted by the Red Sox in 2002 and developed wonderfully in the Minor League system, Lester emerged into a consistent horse in Boston. This, despite the fact he had to overcome cancer at the age of 22 -- at the end of his rookie season in ’06. Not only did Lester make it back to the mound in ’07, but he also won World Series-clinching Game 4 at Coors Field against the Rockies. That night, Lester fired 5 2/3 shutout innings.

In 2008, there was another feel-good moment for Lester when he pitched a no-hitter against the Royals. He was a rock of consistency from '08-13, winning 15 games or more in five of those six seasons. If not for a superhuman performance by David Ortiz, Lester surely would have been the World Series Most Valuable Player Award in ’13, when he won both of his starts while posting a 0.59 ERA.

3. Dutch Leonard, 1913-18
Key fact: Of the lefties who logged at least 600 innings for the Red Sox, his 129 ERA+ is topped only by Grove

You might not have ever heard of Leonard, but we are here to educate you. When Boston was in the middle of a championship renaissance in the 1910s, Leonard was a force. In '14, he had an ERA of 0.96 in 224 2/3 innings. That is still the best ERA of any pitcher since 1900 who qualified for the ERA title. It added up to an astounding 279 ERA+. Leonard also led the league in FIP and WHIP that year.

Teaming up with another lefty named Babe Ruth, Leonard helped Boston win back-to-back World Series championships in 1915 and ’16, and was part of the ’18 team. His .133 opponents’ batting average in the postseason is second in Red Sox history.

Only Smoky Joe Wood (1.99) and Cy Young (2.00) had a better ERA for the Red Sox than Leonard (2.13).

4. Mel Parnell, 1947-56
Key fact: Had 25 wins and 27 complete games in 1949

It’s too bad Parnell didn’t start his career a little bit earlier. The 1946 World Series could have had a better outcome if he had been part of the mix. With Parnell leading the charge in that epic ’49 season, the Red Sox lost the pennant by just one game to the Yankees. He threw 295 1/3 innings and gave up just eight home runs.

Parnell pitched for the Red Sox his entire career, and he is the team’s all-time lefty leader in wins (123) and innings (1,752 2/3). When you look at Parnell’s numbers, he was a machine of consistency much like Lester.

In his final Major League season, Parnell fired a no-hitter against the White Sox. He had to retire after that season with a torn muscle in his left arm. Parnell later became a broadcaster for the Red Sox, and his call in Game 162 of the 1967 season, “Little soft popup, Petrocelli will take it, he does! The ballgame is over! The Red Sox win it! And what a mob on this field!” has been replayed over and over through the decades.

5. Babe Ruth, 1914-19
Key fact: His 29 2/3 scoreless innings in the World Series was a record that stood for 43 years

Long before there was a so-called Curse of the Bambino, Ruth was a dominant lefty starter during some glory years for the Red Sox. The clutch gene he displayed at the plate in all those Fall Classics with the Yankees was ever-present when he pitched for Boston in the World Series. Ruth was 3-0 with two complete games and an 0.87 ERA in World Series starts for the Red Sox.

Ruth was plenty special in the regular season, too, going 89-46 with a 2.19 ERA over six seasons. Without question, he was at his best as a pitcher in 1916, when he led the AL with a 1.75 ERA and nine shutouts in 40 starts. This should come as no surprise, but Ruth was also a dangerous offensive player over 1,332 plate appearances in Boston, slashing .308/.413/.568 with a 190 OPS+.

Ruth’s 2.19 ERA is the best by a Red Sox lefty with at least 1,000 innings. His 105 complete games rank him eighth all-time in franchise history, one spot ahead of Roger Clemens.

Honorable mentions
Given that Chris Sale has an ERA+ of 149 -- the best for a Red Sox lefty with at least 500 innings -- it was agonizingly hard to leave him out of the top 5 on this list. But the competition was stiff, and Sale has only been with Boston for three seasons … Bill “The Spaceman” Lee was surely a character, but he was also a fine pitcher. Lee went 94-68 for some highly competitive Boston teams in the 1970s … Though David Price's four years in Boston included controversy and injuries, the team won the AL East three times during that span. And Price came up huge when the Sox needed him to in the 2018 postseason, turning in dominant performances in clinching games against the Astros in the AL Championship Series and the Dodgers in the World Series … If only the Sox had won it all in 1986. When they were one strike away from beating the Mets, Bruce Hurst had already been voted as MVP of that Fall Classic. Obviously, the voting had to be reversed after the Mets won the series. Hurst had a devastating curveball and was terrific at spotting his fastball. He won 88 games for Boston … Ray Collins pitched for two championship teams in Boston (1912 and ’15) and is fifth in bWAR (24.7) among Red Sox lefties.