The Bedeviling Nate Jones

By the beginning of June, the White Sox season was swiftly beginning to slide into the abyss. The back to back sweeps by the Cubs and A's set the Sox down the dour path for the rest of the season. Nate Jones was one of the many under-performers at the beginning of the season. At 1-4 with a 6.58 ERA, he was beginning to look like yet another young reliever that the league had caught up with. In one of the few positives of the season, Jones turned it around and was able to pull himself out of the Sarlacc.

Since Nate Jones may be the new White Sox closer come next April, how'd he do it? "Coop fixed 'em" is the simple answer, but let's take a little close look?

The Slider

While we all know Jones has elite velocity with his fastball, his work on his slider is what turned his season around. During a game this past season, Hawk Harrelson was talking about his hitting approach. For every pitcher, he tried to figure out one pitch he could just ignore. If he recognized that pitch coming, he would just let it go by and concentrate on the pitches he could hit. At the beginning of the season, that was an excellent approach for dealing with Nate Jones since his slider was a pitch that most hitters could ignore.

This zone map here shows where Jones's sliders went from a catcher's perspective during the first two months of the season. With over 50% of the sliders going outside to right handers / inside for left handers, laying off the slider was an excellent plan. With twelve walks in his first 26 innings during the 2013 season, batters seemed to have this figured out. As the season went on, Nate Jones made a huge improvement in location of his slider.

While the low and away to righties is still the hottest part of the map, it only accounts for 21.99% of the sliders thrown instead of 31.30%. The second hottest zone is now low and away in the strike zone at about 7.85%. Inside the strike zone, Jones raised his percent of sliders from 31.3% to 39%. Low and over the plate also increased from 5.35% to 13.62%. The other part to factor in here is that Jones also threw his slider a lot more often. In the first two months of 2013, he threw his slider just over 29% of the time. The rest of the season, it was closer to 50% of the time. Throwing the slider more and more often for strikes really made it a much harder pitch to ignore and made Jones a much harder pitcher to deal with.

First pitch strikes

The importance of first pitch strikes has been pretty well known for quite a while by sabermeticians. Craig Burley's article on first pitch strikes ends with the the following conclusion.

0-0 is the predominant count in baseball. The first strike is the soul of every pitcher's success, and pitchers who don't throw first-pitch strikes get killed.

Before June 1, 52.7% of Nate Jones's first pitches went for strikes, fouls, or balls in play. After, 65.7%.

Getting 18.2% more strikes from the sinker is an amazing improvement, while the 14.3% improvement with the slider is nearly as impressive considering the zone maps above.

Velocity

Finally, while this wasn't probably a huge factor, Jones did pick up some slight velocity improvements as the season wore on.

That velocity wasn't just during the June and July. In his final appearance of the season, his sinker was over 100. This kind of durability in the bullpen was nice to have considering the velocity losses that Addison Reed had from 2013 to 2012 and during the season as well.

Overall, Jones turned a season that was looking like a train wreck into becoming one of the most dominant relievers in baseball. His slider went from a OK secondary offering into a weapon in line with his upper 90's sinker. He improved his first pitch strikes to force hitters into a defensive mode on the first pitch. Finally, he saw velocity improvements during the season which may not have had as much effect as getting his slider over the plate certainly showed his durability.

*These FIP calculations use the season long FIP constant of 3.048. While not technically accurate, it is a safe enough assumed value for this discussion.