In mid-June I wrote that the Tigers’ starting rotation was on pace to be the best starting staff in MLB history by Fielding Independent Pitching (what’s FIP?) which is a statistic that measures the three true outcomes a pitcher has complete control over and scales it to look like ERA. Based on strikeouts, walks, and homeruns – the Tigers are on pace for an historic season.

If you don’t know much about FIP, click on the link above to see why it’s a better reflection of a pitcher’s true talent than ERA which depends a lot on the defense behind the pitcher. Another statistic, Expected Fielding Independent Pitching (xFIP), considers a pitcher’s GB/FB rate and averages out their HR/FB%, but unfortunately we don’t have batted ball data before 2002. We have FIP data all the way back to the beginning of MLB history. If we start in 1901 and run through Saturday, the Tigers have the third best FIP of all time. What I’m about to show you is FIP-, which is simply FIP adjusted for park effects and league average which allows us to compare teams in different run scoring environments. 100 is league average and a point above or below is a point better or worse than average. A FIP- of 95 is 5% better than average. Here are the top five FIP- in MLB history:

Two months ago, the Tigers had a starting rotation FIP- of 64, and they’ve since come back to the pack because that would have been a crazy good number. Despite struggles from Verlander and a few bad starts from Fister, the Tigers still have the 3rd best rotation in MLB history.

They are getting contributions from everyone in the rotation, too. Here are a series of tweets I send out Saturday night about the Tigers rotation:

The rotation is deep. Here are some basic numbers:

Only Alvarez (and his 20 IP) has a FIP that isn’t at least 14% better than average and all of the main five starters have at least 2.0 wins above replacement or more (what’s WAR?). In fact, despite having an ERA a bit worse than their FIP due to some less than perfect defense behind them, the Tigers rank very well in both all time.

More teams have allowed fewer runs relative to average, but only two teams have ever done so thanks to better pitching. The Tigers aren’t a lock to set this record, but they are pitching very well right now and are currently hanging right around the strikeout rate record as well.

The Tigers are a good team top to bottom with a great offense, but their starting pitching is the flashy component. They have baseball’s best offense and best pitching staff – and the pitching staff might be one of the best all time. I’ve written a lot about the different Tigers starters and what makes them great this season. You can find every one of those pieces in our Tigers Breakdowns section along with a piece about how the Tigers are utilizing the changeup as a weapon more and more.

With 53 games to play, the Tigers are not in position to break the all-time record for FIP, but they are just 1% away from the top mark in history. With just a little better performance than they are on pace for, the Tigers could be the first team to ever have their starting staff pitch 26% better than league average for an entire season. It’s a remarkable record and one that isn’t nearly well-known enough.

National and local writers have made plenty out of the very good Tigers rotation, but with the exception of a piece by Dave Cameron at FanGraphs, I haven’t seen anyone else call attention to just how great this rotation truly is. The Tigers aren’t just pitching pretty well this season, they’re pitching better than all but two rotations in baseball history spanning more than 100 seasons.

With about two months left, this is going to be fun to watch.