Fernando Rodney gave up five earned runs in 74 2/3 innings in 2012. That's an ERA of 0.60. His WHIP was 0.78. The Tampa Bay Rays' closer finished fifth in the voting for the American League Cy Young Award.
A season later, Rodney had already given up six earned runs by May 6.
Jason Grilli was a washed-up 32-year-old right-handed reliever with a 5.32 combined ERA in stints with Colorado and Texas in 2009, and he sat out the following season with a knee injury. On July 21, 2011, Grilli signed a Minor League contract with the Pittsburgh Pirates.
Not even two years later, Grilli is the long-haired, swashbuckling closer of one of baseball's early-season breakout teams, with a National League-leading 23 saves, a 0.98 ERA, a 0.76 WHIP and 46 strikeouts in 27 2/3 innings.
See what we're getting at here?
You can't predict baseball to begin with, but relief pitching, as always -- and when not represented in human form by Mariano Rivera -- remains as confounding as any part of the game and is still seemingly governed by that mathematical overlord, the small sample size. Setup men and closers have to have short memories, and so do astute observers of the sport. Because things can change quickly.
Rodney is a good example of a pitcher who has the tools to be dominant. His fastball still reaches 99 mph. Rodney's changeup works off that fastball as the ideal out pitch. When he's putting the ball where he wants to, he's devastating. But somehow this year, it hasn't come together, just like it didn't come together when Rodney was with the Angels in 2010 and '11 and posted just 17 saves over those two seasons.
In analyzing Rodney's struggles in 2013, some have pointed to his work during a stellar preseason run as the closer for the victorious Dominican Republic team in the World Baseball Classic. Or that last year, Rodney walked 15 batters all season in those 74 2/3 innings. This year, he's already walked 22 batters in 27 1/3 innings.
Rays manager Joe Maddon knows how these things work, which is why he hasn't hit the panic button yet.
"It's not like he's been awful," Maddon said of Rodney, who does have 36 strikeouts. "He has not been awful. It's so close between feeling really good about himself and not feeling good about himself. Physically, he's fine.
"We've been very unfortunate in the latter parts of games. It's not a physical thing. I think it gets more psychological. … Everyone would be smiling and happy right now if we had just been able to finish some games off. Those ninth-inning losses, those are the ones you want to throw in the waste basket."
Grilli was more than happy to throw several years of mediocrity in the waste basket. There was never much doubt that he had a good arm -- Grilli was a first-round selection in the 1997 First-Year Player Draft. But issues with command, injuries and poor timing sapped him of opportunities. He considered pitching in Korea at one point until the Pittsburgh dream scenario unfolded. Now, somehow, even though he's got the ball in the ninth inning, the pressure is off.
"It's very relaxing knowing that you don't have that monkey on your back trying to prove yourself," Grilli said. "And it's obviously nice to have a two-year contract behind you and an organization that believes in you and says, 'This is your job.' I've never really had that in my career."
"I've just got my head down and the foot straight on the gas pedal. Whether it's a good season or bad season, I don't look up until it's over."
That's a healthy attitude for any player but particularly a relief pitcher. After all, nobody in baseball can claim to be surprised that it's a volatile position. A vast majority of pitchers get into the game as starters, and Major League front offices want good starters. So naturally, a pitcher who's a career reliever might not have the right array of pitches, body makeup, durability or repeatability of delivery to be an effective starter.
Hence the relief role and the unpredictability of getting only 50 to 70 innings a year in which to build a good statistical resume.
It happens a lot these days. Pitchers coming off brilliant seasons as closers start off slowly, lose the ninth-inning role and have to pitch their way back. John Axford is experiencing it in Milwaukee right now. Heath Bell already experienced it -- he's rebounding in Arizona.
Bell, who had been so brilliant in San Diego from 2009-11, with more than 40 saves in each season, fell flat in Florida after signing a big contract with Miami and started off poorly in Arizona this year.
But as quickly as the sample-size gods can take away, they can give back. Bell and the D-backs' brain trust, including manager Kirk Gibson and pitching coach Charles Nagy, figured out a simple flaw in Bell's delivery: he was rushing it. He fixed it, mixed in positive thoughts, built on the momentum and has improved steadily since his poor season opener. Bell, who has assumed the role of Arizona closer in the absence of injured J.J. Putz, has a 1.80 ERA and three saves in June.
"I'm starting to feel like my old self back in the day, and the coaches have helped me accomplish that," Bell said. "Sometimes, maybe we're not on the same page, but as long as I explain my thought process, it's OK. We have a dialogue."
The same can be said in Baltimore, where Jim Johnson is experiencing the ups and downs of big league relief. Johnson saved 51 games last year for the surprising Orioles, pitching to a 2.49 ERA.
This year has been rocky so far. Johnson still has plenty of saves (23) but has already blown four. He has rebounded to successfully close out his last eight opportunities, but his ERA is 4.31 and his WHIP is up to 1.231 from last year's 1.019.
Baltimore manager Buck Showalter hasn't wavered from using Johnson in the ninth inning, and that confidence has paid off lately. This attitude is not surprising to the least volatile reliever of all, who's seen it, lived it, and understands better than most that this is a fickle role that requires the thickest skin and a lot of determination.
"We all go through it," Rivera said. "It's normal. If you're a closer and you don't think you're going to go through it, I think you're fooling yourself. You just have to be ready to bounce back, be patient and continue moving."
Doug Miller is a reporter for MLB.com. Follow him on Twitter @DougMillerMLB.