Toolshed: Breaking down FIP in the Minors

This is part of a series of columns we're calling the Toolshed, focusing on some of the more interesting prospect-centered storylines of 2015. Have ideas, feedback or questions for Sam? Email him or tweet him @SamDykstraMiLB.

We've covered power. We've covered speed. Let's make sure the pitchers don't feel left out. 

In our latest look at some of baseball's more advanced statistics, we turn our Toolshed eyes toward Fielding Independent Pitching. FIP's goal is fairly self-explanatory, even if the formula is everything but. What FIP tries to achieve is an evaluation of a pitcher based on the things only he can control. In other words, it doesn't focus on runs or even earned runs, as ERA does, because those stats can be affected by defenses, both positively and negatively.

Instead, it turns the focus on strikeouts, walks, hit batsmen and home runs. You strike out a batter, you control that. You issue a walk or plunk the hitter, you control that. You lay a fat pitch over the plate that the hitter cleans out to the bleachers in right, you control that (mostly). You give up a ground ball that your shortstop can't get to thus allowing two runs to score, you don't control that.

Now FIP is by no means a perfect stat. For instance, it doesn't control for ballpark effects like ERA+. But it is another tool in our analytical bag, and it's certainly worth exploring when we talk about how look at pitching performance.

The formula for FIP is as follows:

FIP = ((13*HR)+(3*(BB+HBP))-(2*K))/IP + constant

FanGraphs breaks the formula down here, but essentially the components of FIP are weighted according to their impact and are added to a constant that is meant to get the stat on the same scale as league ERA. Because we're dealing with multiple prospects who played in multiple leagues, we took data from the 16 domestic circuits and calculated the combined FIP constant for those leagues to be 3.43 for the 2015 season. So when we talk about FIP, just know that's the number we're using in this context.

The FIPs, ERAs, counting stats and per-nine averages for each of the pitchers appearing among MLB.com's Top-100 prospects can be found in these two tables. But let's break down some of the more interesting FIP-related storylines from the 2015 season:

FIP looks good on them

Lucas Giolito, Nationals: Giolito was good in 2015. You know this by his 3.15 ERA. You know this because he rose from his already lofty status as MLB.com's No. 6 overall prospect at the start of the season to his current spot at No. 3. And now you know it because of his 2.63 FIP. Generally, anything below 2.90 is considered excellent, and the Nationals' top prospect beat that mark by a considerable margin. Giolito averaged 10.1 strikeouts, 2.8 walks and only 0.2 homers per nine innings at Double-A Harrisburg and Class A Advanced Potomac in his second full season after late 2012 Tommy John surgery, and those are all numbers that FIP just loves.

The 21-year-old right-hander has already been invited to big league camp with Washington, so although he has virtually no shot of cracking the Opening Day roster, you can bet he's on the radar for a potential Major League debut at some point in 2016 if he puts up similar results and continues to develop as one of the most exciting young arms in the game.

Alex Reyes, Cardinals: Let's hope Reyes' recent 50-game suspension for marijuana hasn't become people's first thought of the Cardinals' top prospect after his stellar 2015 campaign. The 21-year-old right-hander, who combines an incredible fastball with an impressive curveball, led Top-100 prospects with a 13.4 K/9 and allowed only one homer over 101 1/3 innings at three levels. On that alone, it's no surprise his 2.18 FIP was lowest among Top-100 pitchers with at least 50 innings and would have been lowest in our three-year look at FIP, if Carl Edwards Jr.'s eye-popping 1.96 in 2013 didn't edge it out.

Reyes, of course, has thrown only 34 2/3 innings at the Double-A level, so take his 2015 numbers with some salt. But his combination of stats and intangibles proved to be one of the most impressive in the Minors in 2015, and suspension aside, that sets up an intriguing 2016 for Reyes. He could be a candidate to get the Carlos Martinez treatment (a youngster who starts his Major League career in the bullpen, only to move into the rotation once he's settled) in time for a late-season playoff push in the competitive National League Central.

Julio Urias, Dodgers: You'd be right to sense a theme of highly rated pitching prospects because, well, FIP tends to shine well upon good pitchers. Urias, MLB.com's No. 4 prospect, is no exception. The 19-year-old left-hander took another step forward in his development this summer, posting a 9.9 K/9, 2.5 BB/9 and 0.1 HBP/9 over 80 1/3 frames across four different spots. Rough small samples at Class A Advanced Rancho Cucamonga (4 ER in 4 2/3 IP) and Triple-A Oklahoma City (9 ER in 4 1/3 IP) caused his ERA to balloon to 3.81 in the Minors. But FIP looked much better on him at 2.91. In fact, his 0.90 difference between ERA and FIP was the lowest among our qualified group here.

Throughout his four-year career, the now-19-year-old has proven to be adept at racking up strikeouts while keeping walks relatively low and the ball in the ballpark. He's yet to throw more than 87 2/3 innings in the Minors, however, and was limited once again by cosmetic eye surgery in the middle of the 2015 season. We'll have to see what effect bigger samples and the Pacific Coast League will have on the southpaw before he turns 20 in August.

FIP hurts them

Touki Toussaint, D-backs/Braves: It was a rough year by all accounts for the 19-year-old right-hander. He was traded on his birthday to the Braves in what was essentially a Bronson Arroyo contract dump, and although that's not a bad thing given the excitement around the Atlanta system lately, it couldn't have been fun for a teenager to be dealt in his first full season. Despite a fastball and curveball that grade out at 65 on the 20-80 scale, his performance on the field was equally rough as he finished his first season with a 4.83 ERA, 1.36 WHIP, 6.9 K/9. 4.9 BB/9 and 1.0 HR/9 in 87 2/3 innings of Class A ball. Going by our chart, he was in the bottom five among Top-100 prospects in each of those last three stats, and his K/9 wasn't far off either at sixth-worst. So while his 4.83 ERA was highest, the same could be said of his 5.20 FIP. 

Of course, these are early days yet in the still-promising career of MLB.com's No. 69 prospect, and the Braves will be happy to see him try to fulfill that promise in their organization during their rebuild. But there are several issues that need to be worked out in his second full season next summer. 

Tyler Kolek, Marlins: Another theme -- 2014 first-rounders who didn't get off to great starts in their first full seasons. Kolek -- the No. 2 overall pick that year and the highest pick to actually sign -- experienced several similar issues to Toussaint. The 6-foot-5 right-hander's fastball is as fast as it gets in the lower levels of the Minors and can easily touch triple digits, but the pitch alone wasn't enough to strike out South Atlantic League batters at a great clip with Kolek averaging just 6.7 K/9. Toss in some rough control problems that saw him issue 5.1 BB/9 and 1.1 HBP/9, and that's how he ended up with a 4.82 FIP that was even worse than his 4.56 ERA in 108 2/3 innings for Greensboro. The Marlins still have big plans for their top prospect and hope these are nothing more than just growing pains for now, but it hasn't been an easy transition for Kolek thus far.

Duane Underwood, Cubs: Underwood looked like he put it all together in his first season at Class A Advanced Myrtle Beach, going 6-3 with a 2.41 ERA and 1.01 WHIP in 78 1/3 innings mostly in the Carolina League after taking a relatively slow road over his first three years in the Cubs system. Indeed, he moved up from No. 8 in the Cubs' prospect rankings to No. 4 and even avoided Tommy John surgery despite right elbow inflammation that kept him out nearly two months, so it was all mostly good news in 2015 for the right-hander. 

Here's where it starts to fall apart a little bit. Underwood was not an adept strikeout artist this season and fanned only 6.2 batters per nine innings. (If you don't include his rehab appearances in the Arizona League, that number ticks down even further to 5.9.) Without any other incredible FIP-related stat to save him, his FIP stands at 4.12, which is as "meh" as you'd consider a 4.12 ERA to be. The 2012 second-rounder benefited from an extremely low .223 BABIP (batting average on balls in play) that helped keep runners off the basepaths and runs off the board. However, if he can't find a way to miss more bats in 2016, his relatively low ERA will likely match his relatively high FIP in the upper levels, once his BABIP normalizes. 

Aaron Blair, D-backs (now Braves): Blair's numbers (2.92 ERA, 1.17 WHIP, 2.8 BB/9) were pretty solid at Double-A Mobile and Triple-A Reno in what would be his last season in the D-backs system before being dealt in the Shelby Miller trade. But his strikeout totals, once a strength, took a dive as he averaged only 6.7 K/9, and his FIP suffered with a jump to 4.00 between the two spots. By his own admission, Blair was trying to pitch to more to contact against the tougher competition of the Minors' two highest levels, and from a traditional stats point of view, the strategy worked. But you'd have to expect Atlanta will try to get him to miss a few more bats and not be so BABIP-reliant -- Double-A hitters had just a .265 average on balls in play against him in 2015 -- going forward in order to help him hit his ceiling as No. 3 starter, perhaps as early as this season.

Other notes

• If you're looking at our table, don't be fooled by Blake Snell's 1.47 increase from his ERA to his FIP. The Rays left-hander's year was so good by way of his 1.41 ERA -- helped by a 46-inning scoreless streak to start the season -- that his FIP was bound to look worse by comparison. However, his 2.91 FIP was still 10th-best among Top-100 prospects with at least 50 innings. For comparison (albeit at severely different levels), Dallas Keuchel posted a 2.91 FIP for the Astros in his Cy Young-winning campaign.
• If you're a Phillies fan hoping that new acquisiton Mark Appel's 2015 will look better by way of FIP, sorry to be the bearer of bad news. Appel's 4.34 FIP was third-highest among Top-100 prospects with at least 50 innings. Part of that has to do with playing in the Pacific Coast and Texas Leagues, which both ranked in the top four among Minor League circuits for homers in a game. Indeed, Appel's 0.9 HR/9 rate hurt his FIP in a big way, as did his lackluster 7.5 K/9. He's likely ticketed for Triple-A Lehigh Valley to start 2016, and that should help him cut down some on the homers allowed, but it'll take more than just that for the results to match the right-hander's impressive stuff.
• New Dodgers acquisition Frankie Montas posted a 2.97 ERA in 112 innings as a starter at Double-A Birmingham in the White Sox system and was similarly solid with a 3.16 FIP over that span, second-best in the Southern League among qualified hurlers. Those looking for more evidence that the 22-year-old's future role is in a rotation and not the bullpen would be well served to take note.