clock menu more-arrow no yes

Filed under:

Analyzing “The Bone Effect”

New, comment

With his contract expiring, we look to see if the numbers support an extension for Marlins infield wiz Perry Hill.

MLB: Cincinnati Reds at Miami Marlins Steve Mitchell-USA TODAY Sports

When “The Six F’s of Fielding” are mentioned, one name comes to mind: Perry Hill. Widely regarded as a defensive guru, Hill has spent six straight seasons on the Marlins coaching staff and 12 seasons with them overall since 2002.

A former second baseman who treaded water in the Mexican League before becoming a coach in 1984, Hill cultivated his knowledge of fielding with the Tigers, Expos, Florida Marlins, and Pirates, before becoming a fan favorite for the Miami Marlins.

The Six F’s is Perry Hill’s manifesto on infield technique. He sells his technique on his website, so it’s extremely hard to find a video of him explaining what it is. Nevertheless, the Six F’s are:

Feet—how an infielder sets his feet prior to a batted ball.

Field—actually fielding the ball; how an infielder positions his glove and free hand to receive the grounder.

Funnel—transitioning from fielding the ball to preparing to throw by bringing the ball and glove into the belly button. This process essentially forces the fielder to have soft hands; programming this step into a fielder’s repertoire prevents them from stonewalling the ground ball on contact with the glove.

Footwork—the infielder resets his feet and begins footwork towards the base he’s throwing to.

Fire—actually throwing the ball

Follow through—continuing momentum through the throw. Like the funnel feature, this last step essentially forces an infielder into not making an off-balance or back foot throw.

The technique has worked, and the numbers back it up. In 2018, the Marlins ranked 9th in team Defensive Runs Saved with 27 runs saved and 13th in Ultimate Zone Rating at 8.1 runs above average. But to be more specific, the Marlins’ infield saved 22 runs according to DRS and 31.2 according to UZR. That’s elite performance you wouldn’t normally expect from a rebuilding team.

This year was no outlier—Hill’s infield has always been notoriously tight. Other clubs have noticed, Ken Rosenthal reports, and hope to pursue him as a coaching free agent when his contract expires this month.

How much credit does Perry Hill deserve for his players’ glovework? Should the Marlins make it a priority to get a new deal done with him?

There is no better testament to Hill’s experience and wisdom than the bump that individuals get when they play for him.

Starlin Castro

MLB: Cincinnati Reds at Miami Marlins Jasen Vinlove-USA TODAY Sports

Starlin Castro is a perfect example. A long time ago in a galaxy far, far away, Castro was an up-and-coming shortstop in the Cubs system. From 2010-2014, Castro racked up 1000+ inning seasons at shortstop and for the most part recorded miserable advanced defensive metrics. Then Addison Russell came of age in 2015 and bumped Castro to second.

Castro was moved to the Yankees shortly after in 2016, where he remained at second base.

Starlin Castro, Second Base Defensive Metrics

Year Team Perry Hill? Innings FP DRS UZR
Year Team Perry Hill? Innings FP DRS UZR
2016 Yankees No 1266 0.98 -8 -4.1
2017 Yankees No 936 0.973 -6 -5.9
2018 Marlins Yes 1314 0.981 0 0.5

We’ll primarily be using UZR and DRS for the rest of the article because, as you can see, fielding percentage doesn’t avail us to any significant trends (and comes with a variety of other problems). You can read about UZR and DRS on Fangraphs. What’s important to know for now is that for both metrics, players get incrementally credited and penalized on a cumulative, season-long basis for the plays they make and fail to make. After that, infielders receive bonus points for their abilities to turn double plays, the number of great fielding plays they make, the errors they commit, and the range they exhibit, depending on what system your using.

Castro saw gains in almost all of his fielding metrics. From last year to this year, he improved from costing the Yankees three runs on plays made, to saving the Marlins one run.

It appears that Castro’s biggest issue with the Yankees was his ability to limit errors, marked by his 2017 Plus/Minus Runs Saved of -3 and Error Runs of -3.8. In UZR terms, from 2017 to 2018, he not only reduced his Error Runs from -3.8 to -1.0, but also increased his Range Runs from -0.5 to 1.3. DRS melds Range Runs and Error Runs into Plus/Minus Runs Saved, and then accounts for Great Fielding Plays independently.

You’re probably furrowing your brow and saying, “OK Mitchell, there are 1,000 other factors that can play into Starlin Castro’s one-year improvement, other than him being coached by Perry Hill.”

You’re right, and with metrics like UZR and DRS, we prefer to analyze the numbers over three-year samples. But you can’t eliminate Bone from the equation yet.

Let’s continue...

Adeiny Hechavarria

MLB: Miami Marlins at Washington Nationals Brad Mills-USA TODAY Sports

Adeiny Hechavarria has always been known for his defense. Coming up in the Toronto Blue Jays farm system, Hechavarria raked in a bevy of minor league defensive accolades from Baseball America. He came to Miami in the 12-player blockbuster of 2012, and the Marlins made him into their everyday shortstop.

Adeiny Hechavarria, Shortsop Defensive Metrics

Year Team Perry Hill? Innings DRS UZR UZR/150
Year Team Perry Hill? Innings DRS UZR UZR/150
2013 Marlins Yes 1297.1 -3 -1.9 -2.1
2014 Marlins Yes 1294.2 -3 -8.1 -7.9
2015 Marlins Yes 1120.1 9 10.6 12
2016 Marlins Yes 1222 9 6.6 7
2017 MIA/TB Kinda 813.1 5 4.5 9
2018 TB/PIT/NYY No 717.1 3 1.7 4.3

As you can see, despite the flash in the glove, Hech was a wild horse who needed to be broken in his first two years. Perry Hill was just the guy to do it. Although inferably Hech had serious potential for range, he wasn’t able to convert tough ground balls into outs. Take 2014 for example, when Hechavarria recorded a then-high watermark in fielding percentage, but still cost the Marlins four Plus/Minus Runs Saved according to DRS. UZR supports this hypothesis as well; Adeiny saved 1.8 Error Runs for the Fish in 2014, but cost them 6.6 Range Runs. This anchored his UZR down to -8.1 for the season.

Hechavarria quite suddenly came into his own in 2015. His DRS and UZR were good enough for fifth-highest and second-highest among shortstops that year, respectively. As far as DRS goes, his Plus/Minus Runs Saved ballooned up to 11. In terms of UZR, Hech’s range runs improved from -6.6 all the way to 4.9. He also saved 4.5 Error Runs. Hech maintained this consistency in 2016.

What has happened since Hechavarria left Perry Hill’s side? He’s experienced a slight decrease in defensive efficiency. It’s probably not a significant one (he has been a plus defender all of 2018) but it’s one nonetheless. UZR/150 deals with any disparities in sample size by pro-rating his would-be UZR over 150 games. This stat indicates that Hech has indeed played poorer defense since his last half-year with Bone. His departure in range runs—back to the negative—is particularly noteworthy.

Again, is Hill totally responsible for this? Likely not. Hech hasn’t gotten nearly as consistent playing time with the Pirates, Rays and Yankees as he did with the Marlins.

The focal point of Hechavarria’s analysis here is his abrupt maturation in fielding in 2015. Young prospects are in constant need of molding as they make their transition to the big leagues. Hill was a central influence on Hechavarria’s coming to as one of the game’s best defenders.

Miguel Rojas

Miguel Rojas has been an extremely integral utility player for the Marlins since he joined the club in 2015. He is capable of playing every position on the infield. With that said, he never really got a true shot at shortstop until last year, and even so, he still shared time with JT Riddle. That was the case again this year.

Miguel Rojas, Shortstop Defensive Metrics

Year Team Perry Hill? Innings DRS UZR UZR/150
Year Team Perry Hill? Innings DRS UZR UZR/150
2017 Marlins Yes 612.2 3 1.4 3.1
2018 Marlins Yes 657.1 10 5.9 13.6

The 600+ innings that he accrued at shortstop the past two years are the most he’s accrued at a single position in a season. In his first season at the most challenging infield position, he accrued modest, positive numbers in both UZR and DRS.

This year, Rojas was one of the best defensive shortstops in the league. Rojas’ DRS of 10 ties Dansby Swanson for 4th highest in the majors. His UZR also ranked 6th highest. The most remarkable aspect of these stats is the fact that Rojas has at least half the amount of innings played than any other shortstop in the top ten in DRS or UZR. Recall that DRS and UZR are both counting statistics so naturally, more innings played leads to higher totals for both categories.

The fact that Rojas breached the top ten in half the sample of all the other top defensive shortstops is really incredible. When Rojas’ UZR is pro-rated over 150 games, he ranks second in the league, trailing only Andrelton Simmons.

Everywhere else over his entire career, Miguel Rojas has only recorded a negative UZR and DRS once: in 2016 at shortstop. His ability to fill in at any position on the diamond with above average defense has been crucial for a team with frequent lineup gaps.

Rojas spent about eight years in the minors with the Reds and Dodgers before coming to Miami and learning the dark arts from Hill in 2015. You think Miguel Rojas owes any of his defensive prowess to him? Watch Rojas at 0:28 in this video:

Rojas over-exaggerates the Six F’s, which is a good thing. Any gifted baseball infielder has the hands to adequately field a ground ball. The next step is mixing in technique. Rojas’ hands are filthy—this is clear if you’ve ever seen him play catch with Martín Prado before a game. But as a notorious student of the sport, Rojas takes the next step by closely adhering to Bone’s teachings. The proof is in the pudding; the numbers show that Rojas has been an extremely prolific defender.

Good coaches matter on baseball teams. The Los Angeles Dodgers have Turner Ward, a King Midas who has rejuvenated the careers of hitters like Justin Turner, Chris Taylor and Max Muncy, among many others.

Hitting is easy to see, above-average fielding is not. We remember the highlight reel plays, but we don’t truly appreciate an infield getting the job done behind a pitcher.

Perry Hill’s infields have gotten the job done for eight years now. It may seem tiresome and redundant for a coach to start from square one and teach something like The Six F’s to twenty-somethings who get paid millions of dollars to field ground balls. But the players do benefit from the guidance, and the game’s best appreciate and capitalize on it.

The Marlins front office has come under scrutiny for dismissing certain employees in the past year. They don’t have full control over this situation, as Hill would certainly be justified in taking a bigger payday somewhere else if the opportunity presented itself.

But no excuses: the Marlins should at least make an offer to Hill to continue in his role for 2019 and beyond.

Statistics courtesy of