When Ubaldo Jimenez signed his four-year, $50 million deal with the Baltimore Orioles late in the 2014 off-season, people were surprised. The Orioles had never made a commitment to a starting pitcher longer than three years, they would have to sacrifice the 17th overall pick in the next year's draft (eventually used on Brandon Finnegan, who pitched in that season's World Series), and Jimenez was only a year separated from the worst year of his career.

Not much in the 2014 season allayed those concerns. He posted a 4.67 FIP, and by far the worst walk rate of his career (13.9 percent). His four-seam fastball's velocity continued to fall, to 92.3 MPH (per Brooks Baseball), and his 59.8 percent strike rate was the second-lowest of his career (per Fangraphs). This resulted in the 9th-worst ERA among starters with at least 120 innings pitched, and he was placed on the DL in July with a sprained right ankle.

Expectations were minimal for the 2015 season. However, Jimenez has likely surprised anyone checking in on his stat line to this point of the season with a 3.19 ERA, 3.50 FIP, and a 3.55 SIERA, the best of his career, culminating in 1.3 fWAR.

What caused this unexpected success? His 48.4 percent ground ball rate is back in line with his best early-career seasons with the Rockies. Jimenez also has an above-career average 23.1 percent strikeout rate and a career-best 8.4 percent walk rate to date. Those numbers have been buoyed by a career-best 62 percent strike rate (career-average of 61 percent).

Ubaldo Jimenez has a relatively unique repertoire in that he frequently throws five different pitches. In 2015 , that means a four-seam fastball, s inker , slider, split fastball, and curve. This season, he has made some changes to his typical pitch usage.

A sparingly-used cutter, introduced during the 2013 season with the Indians, has been all-but-removed. Jimenez' s inker has rega i ned its early-career use rate. To do that, he has relied less on his four-seam fastball and slider, and now uses the s inker alm ost half the time.

Pitch Type 2013 2014 2015 Fourseam 21.5% 18.5% 12.0% Sinker 30.9% 40.2% 48.5% Slider 24.9% 20.7% 16.8% Curve 3.8% 3.6% 4.1% Cutter 1.4% 0.1% 0.3% Split 17.6% 16.5% 17.6% Change 0.2% 0.6%

The s inker has generated an ab o ve-career-average n u mber o f gr ou nd balls t his season (52.8 percent). Additionally, Jimenez's primary secondary pitch, the slider, is also getting a lot more gr ou nd balls than usual (57.1 percent in 2015 vs 39.5 percent for his career). He is throwing several of his pitches for strikes more regularly, notably the slider and the split fastball.

2015 Career FT 62.3% 62.2% FA 60.0% 62.2% SL 62.4% 59.3% FS 68.8% 59.3% CU 48.9% 52.6%

Having a range of pitches to attack hitters with is a large part of the reason why Jimenez has relatively small platoon splits for his career (.310 RHP wOBA vs .317 LHP wOBA). The knock on him has always been his inconsistent command and the resulting walks that pile up. Early in 2015 that command has been there, and the results have followed.

There is no talk right now about eating salary to move Jimenez's contract, because a Ubaldo Jimenez that commands his secondaries in this way is still a dangerous pitcher to face. He is certainly proving it with his results.

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Spencer Bingol is a Contributor at Beyond the Box Score. You can follow him on Twitter at @SpencerBingol.