When describing starting pitchers, we often say things like "he's an ace" or "he's a #4 pitcher". A pet peeve of mine is the wrongful labeling of a pitcher to a certain rotation spot, based on subjective perception rather than objective fact. Poll a group of baseball fans about this topic and you will likely receive a vast array of opinions. My take, which is similar to the ones shared in this post and this post, is that if a pitcher is in the top 1/5 of starters in his league, then he should be called a #1 starter. The next 1/5 are #2's, the next 1/5 are #3's, etc. I pulled some statistics from FanGraphs to devise a quick and dirty way of classifying National League starters at the halfway point of the season (the Mets have played 81 games, hence I'm calling this the halfway point).

A total of 7,613 innings were thrown by 121 different NL starters through Sunday. I put together a spreadsheet of all these pitchers, their innings pitched, and their FIP (fielding independent pitching). Dividing 7,613 by 5, I created 5 groups of 1522.2 innings. Beginning with the pitcher who boasts the best FIP (P.J. Walters, 1.04 FIP through 4 innings pitched), I summed innings until reaching 1522.2 to determine #1 pitchers. I did the same all the way through the bottom spot on the list, filled by John Koronka and his 11.90 FIP. Standard caveats apply here -- FIP doesn't account for batted balls like tRA, it isn't park adjusted, etc., but it's better than ERA for evaluating a pitcher's performance. Here are the results, showing pitcher classification, the number of pitchers that fit that classification, and the corresponding FIP:

Keep in mind that of the top 22 pitchers, only 9 have thrown at least 100 innings. Rodrigo Lopez owned the Mets on Friday night and has a 2.25 FIP through 6.1 innings, but calling him a true #1 is a stretch. Here is how the Mets' pitching staff stacks up, using this method:

While it's true that Jon Niese should be freed from his minor league shackles, it's doubtful he would mantain his high #1 status. This means the Mets' best starter has been the equivalent of a low #2 pitcher, and most innings pitched by starters have been by #4 and #5 types. Only 14 starters have been worse than Ollie, but he'll get a shot to improve on that starting Wednesday night. Peruse the spreadsheet if you like, and here are some notable names and their classifications:

#1

• Tim Lincecum
• Javier Vazquez
• Chris Carpenter
• Dan Haren
• Josh Johnson
• Ricky Nolasco (he's baa-aack)

#2

• Cole Hamels
• Yovani Gallardo
• Derek Lowe
• Aaron Harang
• Ted Lilly

#3

• Carlos Zambrano
• Roy Oswalt
• Johnny Cueto (maybe not after last night's Phillies shellaquing)
• Randy Wolf
• Ryan Dempster

#4

• Aaron Cook
• Barry Zito
• Chris Volstad
• John Lannan
• Edinson Volquez

#5

• Rich Harden
• J.A. Happ
• Jeff Suppan
• Braden Looper
• Jamie Moyer
• Brett Myers