Of all the different types of players in baseball, I really think a reliever's value may be the most difficult to understand. It's not a mystery why though. They get the least amount of playing time. Typically even the most worked reliever is still only going to throw 70-80 innings. Because of that, it's very easy for their performances to vary wildly from year to year. It's also very easy for their seasons to turn to crap because of 1 or 2 bad outings. For a prime example of that just look at Rob Wooten's 2014 season at the major league level.
Wooten made 40 appearances, pitching a total of 34.1 innings. He season ERA was a whopping 4.72! He must have sucked hard, right? Well, I'll grant that he wasn't excellent. However he only allowed runs in 11 of his outings. In those outings, only 3 times did he allow more than 1 run. In those 3 outings, twice did he allow more than 2 runs. It's those two outings that really tanked his season.
On April 17th he allowed 3 runs in 0.1 innings pitched. He faced 5 batters and gave up a 3 run home run.
On June 15th he allowed 5 runs without recording an out (0 innings pitched). He faced 6 batters and gave up 6 hits.
Wooten actually gets a pretty good grade by FIP, xFIP, and SIERA. In 2014 he had a 2.61 FIP, 3.27 xFIP, and a 2.98 SIERA. Fangraphs gives him a solid 0.5 WAR. Baseball Prospectus gives him a 0.3 WAR. Only Baseball Reference pegged him as a negative contributor with a -0.1 WAR.
I'm not sure which rating is more fitting. His 19.7 K% was close to the league average of 20.4%. His 5.3% was better than the league average of 7.6%. He had a very nice 53.3 GB% and an impressive 0.26 HR/9 (that 3-run home run was the only HR he allowed all season). However his .306 BAA was pretty atrocious and his 1.46 WHIP wasn't any better. League average is .247 and 128 respectively.
Rob Wooten's cardinal sin, to some, was his velocity. His fastball sat around 88-89 mph. There are a lot fans out there that will see velocity that low out of the bullpen and dismiss him without a second thought. To me it doesn't matter quite as much. He just can't make mistakes. When that happens he's shown the capacity to have meltdown innings. He does have 3 other pitches to throw (splitter, slider, curve) which I think helps him survive with his velocity.
Rob Wooten was definitely not a high leverage reliever. He wasn't even a solid middle reliever. I do think he was better than awful though. For most of 2014 he was actually pretty solid.
Um, I actually like Rob Wooten but even I don't think he had a game that qualifies as "best game." Sorry, but he was a low leverage reliever that was used pretty situationally. Maybe his game on July 12th qualifies. He pitched 2 scoreless innings against the Cardinals who happened to destroy the Brewers 10-2.
Rob Wooten is still in his pre-arb years. The Brewers will have team control over him through the 2019 season.
Statistics courtesy of Fangraphs unless otherwise noted