Miami Marlins: David Phelps is becoming a bullpen ace

Jun 1, 2016; Miami, FL, USA; Miami Marlins relief pitcher David Phelps (35) throws against the Pittsburgh Pirates during the eighth inning at Marlins Park. Mandatory Credit: Steve Mitchell-USA TODAY Sports
Jun 1, 2016; Miami, FL, USA; Miami Marlins relief pitcher David Phelps (35) throws against the Pittsburgh Pirates during the eighth inning at Marlins Park. Mandatory Credit: Steve Mitchell-USA TODAY Sports

David Phelps has quietly blossomed into a bullpen ace for the Miami Marlins in 2016 after spending the majority of his career as a starter.

In recent memory, Wade Davis has been the main player that has gone from a mediocre starting pitcher to become a dominant bullpen ace.

As the MLB has always been a copy-cat league, teams have tried to see which of their starters could be thrown into the bullpen and start to perform better in a new role. The Miami Marlins are one of those franchises that have tried this approach.

And boy has it been a swell experience for the Marlins so far in 2016 with David Phelps emerging as a bullpen star.

Originally acquired in the Nathan EovaldiMartin Prado swap between the New York Yankees and Miami Marlins during the winter of 2014, Phelps had started for the Marlins last season, but a season ending elbow injury last year may have forced the team’s hand in trying Phelps out of the bullpen.

Phelps as a reliever only this season has been a smashing success. In 30 2/3 innings, including 2 2/3 innings of work Wednesday night, Phelps owns a 1.76 ERA and a 1.65 FIP, good for a 1.2 fWAR.

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His fWAR actually leads the major leagues this season for relievers. Phelps 1.65 FIP ranks 8th in baseball among relievers.

A big reason for the emergence of Phelps becoming successful out of the bullpen is the fact he is able to ramp up his fastball more this year, pitching less innings and less pitches per appearance.

Here is a quick glance at a velocity chart of Phelps the past two seasons.

PHELPS, PITCH2015 VELOCITY (MPH)2016 VELOCITY (MPH)
Four-seam fastball   91.4  93.9
Two-seam fastball   90.7  93.2

As Michael Jong of Fishstripes points out, an increase of two miles per hour on a fastball could make a significant difference for a relief pitcher like Phelps.

That is an increase of two mph when most pitchers are throwing slightly slower than they would be expected to toss. Such a velocity increase is significant in a pitcher and could help explain why his performance is so improved. The research has estimated a 0.3-run ERA improvement for every increase in one mph of velocity. Such a change would drop Phelps’s expected ERA by 0.75 runs.The numbers bear this out in terms of missing bats. The whiff rate for his four-seam fastball has gone up from 13 percent last year to 29 percent this year, more than double its previous. This is likely playing a big role in his performance increase.

Being able to go all out more often has been a net positive move for Phelps. He can max out his fastball and that has led to an increase in whiffs for him. As a pitcher that has always been able to keep his walks at a decent rate, an increase in strikeouts has been the key to his season.

Phelps 11.45 strike outs per nine innings rate ranks 29th in the league this season for relievers. His 32.5 strikeout percentage ranks 25th in the league.

The added speed and not having to worry about going through a lineup multiple times has allowed Phelps to ramp up his fastball usage to 37.7 percent in 2016. That is up over eight percentage points from 2015.

As a result of all of this, as of Tuesday night’s games, Phelps fastball has been worth 8.3 runs. Last season, his fastball was worth -3.7 runs and -8.2 the season prior to that.

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Not only has his fastball velocity increased, Phelps has also added at least one mile per hour on his slider, changeup, and knuckle curve pitches.

After Carter Capps went down with an elbow issue which eventually required Tommy John surgery and Mike Dunn began the season on the DL, Phelps has been the saving grace, as well as the bridge for the Marlins bullpen to set up closer A.J. Ramos.

David Phelps has been one of the better untold stories of the 2016 season. He has gone from being a fringe major league player, barely holding onto a rotation spot with the Yankees and Marlins to now an emerging star out of the Marlins bullpen.

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With the Marlins not seeming like a major threat to be a playoff team in 2016, one has to wonder if the team will take advantage of the season Phelps is having and look to move him at the trade deadline, where his trade value may be near its peak.