A's fans like myself really appreciate Andrew Bailey.
The rookie right-hander has emerged from obscurity to become one of the best relievers in baseball this season. Using a devastating cutter/curveball combo, Bailey has carved up the American League with a 2.67 FIP.
That said, Bailey's not the best reliever on the team. And the guy better than him doesn't get nearly as much recognition.
Michael Wuertz has been the best reliever on the A's.
I know Bailey's got the saves and the flashier ERA, but bear with me.
Michael Wuertz has always been very good, but nobody really noticed him on a Cubs team that had a lot of big names.
He's sort of an odd pitcher. Wuertz rarely throws his fastball, even though it's not a bad pitch at 89-93 mph. Instead, he throws his slider over 60 percent of the time, essentially reversing the "traditional" roles of the fastball and the slider.
Most relievers try to get a fastball over for strike one and strike two, and then finish batters off with the slider. It's not uncommon to see Wuertz do the opposite.
Wuertz's slider has been worth about two runs per 100 pitches throughout his career, according to Fangraphs.com's Pitch Type Linear Weights. This year, it's at a stellar 2.59 runs per 100 pitches.
In practical terms, that means for every 100 sliders Wuertz throws, he allows 2.59 fewer runs than an average pitcher would. That's a truly excellent number.
Wuertz's odd slider-heavy approach may not garner him lots of acclaim, but he deserves it. He's had sub-4.00 FIPs in four of his six big-league seasons, including a ridiculous 2.50 mark this year.
Wuertz has struck out 45 batters and walked just 10 in 39 innings. He's allowed only three homers, as well.
Bailey, the A's All-Star representative, strikes out fractionally fewer batters (10.38 K/9 to Wuertz's 10.54), but he does have a slightly lower home run rate (.55 HR/9 to Wuertz's .69).
However, the big difference between the two is walk rate, as Bailey's 3.51 BB/9, while good, is much worse than Wuertz's 2.31 mark. Because he walks fewer hitters, Wuertz has the lower FIP, as his 2.50 mark bests Bailey's 2.67.
Still not convinced Wuertz is better? Let's look deeper and check out the batted-ball splits.
Wuertz's numbers all look in line with his career averages and MLB norms, except for one. 17.1 percent of groundballs off the slider specialist have gone for infield hits, more than double his career mark in that category. Wuertz has gotten unlucky, as several softly-hit grounders off him have gone for infield hits.
It's a minor detail, but all it does is make Wuertz look even better.
Bailey's numbers look normal as well, except for one. Just 5.7 percent of outfield flies off Bailey have gone for home runs. Usually, MLB pitchers will have rates between seven and 13 percent in this category. If less than seven percent of outfield flies are homers, the pitcher's getting lucky; if more than 13 percent are homers, the pitcher's getting unlucky.
Bailey's been a bit lucky. Like Wuertz's infield hit ratio, it's not a big deal, but it does make Bailey slightly worse than his FIP indicates.
In terms of who should be an All-Star, Wuertz is the obvious pick because he's pitched better despite being less lucky. Throw in the fact that Wuertz has proven that he's a good MLB reliever with five prior seasons, and it's really a no-brainer.
While Bailey may be the "flashier" pick, he simply hasn't pitched as well as Wuertz in the past or the present. If Joe Maddon wanted to pick a reliever to represent the A's, he should have picked Wuertz, not Bailey.