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.

Here is Anthony DiComo’s ranking of the top five left-handed starting pitchers in Mets history. Next week: relievers.

• Mets All-Time Around the Horn Team: C | 1B | 2B | 3B | SS | LF | CF | RF | Bench | RHP

1. Jerry Koosman (1967-78)
Key fact: Second in Mets history behind Tom Seaver in shutouts, complete games and innings pitched

While nearly every meaningful Mets pitching record belongs to Seaver, Koosman sits immediately below his former teammate in most of those categories. A two-time All-Star who finished second in National League Cy Young Award voting in 1976, Koosman posted his two best statistical seasons almost a decade earlier, when he went 36-21 with 33 complete games, 13 shutouts and a 2.18 ERA over 504 2/3 innings from 1968-69.

As the Mets’ longtime No. 2 starter behind Seaver, Koosman was the winning pitcher for three of their seven World Series victories in 1969 and ’73. He finished his career undefeated with a 2.39 ERA in Fall Classic play.

The Mets announced last year that they intend to retire Koosman’s uniform No. 36 in the near future, making him and Seaver the only pitchers in franchise history to receive that distinction.

“I’m enormously proud of the time I played in the orange and blue uniform of the Mets,” Koosman said earlier this year. “To know that my number will be retired and sit alongside other legends is one of the greatest tributes I could ever be granted. I was always proud to be a Met.”

2. Jon Matlack (1971-77)
Key fact: The Mets’ all-time ERA leader among lefty starters

Often overshadowed by Seaver and Koosman in franchise lore, Matlack made his most indelible mark with a two-hitter in Game 2 of the 1973 NL Championship Series against Cincinnati’s “Big Red Machine.” He didn't allow an earned run over his first 25 innings that postseason before cracking for four earned runs in Game 7 of the World Series, which did little to tarnish his legacy as one of the greatest lefties in Mets history. Over seven seasons, Matlack won 82 games with a 3.03 ERA, making three All-Star Games and winning All-Star co-MVP honors in 1975.

Like Seaver and Koosman, Matlack left New York in a trade amid disagreements with management at the dawn of free agency. Had he stayed, he would have rated even more prominently in the Mets’ record books.

3. Sid Fernandez (1984-93)
Key fact: His 1.11 WHIP is the lowest in Mets history by a left-handed starter

Lists of the best trades in Mets history often gloss over the deal to acquire a 21-year-old Fernandez from the Dodgers for two relatively inconsequential pieces in 1983. Fernandez quickly blossomed into a cog of the Mets’ rotation, winning 98 games with a 3.14 ERA over 10 seasons, while making NL All-Star teams in '86 and ’87. Pitching in relief in the ’86 World Series, Fernandez recorded seven consecutive (and critical) outs in Game 7, striking out four of the eight batters he faced.

When the Mets’ juggernaut fell apart in the early 1990s, it wasn’t because of Fernandez, who actually grew stronger, posting a 2.97 ERA over his final five years with the team.

4. Al Leiter (1998-2004)
Key fact: Ranks fifth in Mets history in pitching WAR (28.0)

In terms of ERA+, which is adjusted for league and park factors, Leiter’s 1998 season was the best in Mets history by any starter not named Seaver, Dwight Gooden or Jacob deGrom. Leiter went 17-6 with a 2.47 ERA that summer, finishing sixth in NL Cy Young Award voting. He then eclipsed 200 innings in three of the next four years, delivering six quality starts in seven tries during the 1999-2000 postseasons (the exception being his five-run blowup on short rest in Game 6 of the 1999 NLCS). Now a front-office advisor, Leiter ranks sixth in Mets history in wins and eighth in strikeouts.

5. Bob Ojeda (1986-90)
Key fact: Went 2-0 with a 2.33 ERA over four postseason starts in 1986

Statistically, Ojeda did not impact the Mets as much as Johan Santana, who is listed in the honorable mentions below. But he jumps ahead of Santana on this list because of what he did during the 1986 postseason, pitching a complete game in Game 2 of the NLCS and holding Boston’s offense in check in Games 3 and 6 of the World Series. Particularly considering Gooden’s struggles in the ’86 Series, the Mets may not have won without Ojeda, whose presence also allowed manager Davey Johnson to use Fernandez out of the bullpen. Ojeda also finished fourth in NL Cy Young Award voting that season, posting a 3.12 ERA overall in five years with the club.

Honorable mentions
Had he stayed healthy, or come to the Mets earlier in his career, Johan Santana would surely have ranked higher on this list. As it was, he gave the Mets 88 excellent starts before succumbing to shoulder woes in 2010. Santana’s comeback in '12 included the only no-hitter in franchise history. … Aside from Koosman, the only Mets left-hander to win 20 games in a season is Frank Viola, who accomplished the feat in 1990. But like Santana, Viola gave most of his best years to the Twins. … Tom Glavine’s reputation as a Met is unfairly tarnished by his performance in the final game of the 2007 season. Over the other 1,000-plus innings of his Mets career, Glavine was a solid contributor and clubhouse leader. … Quietly, Steven Matz has developed into one of the Mets’ best lefties, with a chance to shoot higher if he succeeds in the coming seasons.