The Baltimore Orioles steamrolled their way through the AL East en route to a 96-66 record and an AL East championship, their first since 1997. They won the division by 12 games and were the first American League club to clinch their place in the postseason. A lot of attention will be given to the Orioles' offense this week, and rightly so.
However, the rotation has done their part as well. They may not have the star power that the Tigers' front four have, but are solid from top to bottom. Chris Tillman leads the rotation and will be the Game 1 starter, but the order from there is anyone's guess. Manager Buck Showalter still hasn't announced who will start Games 2 through 4, but the expected order is Wei-Yin Chen, Miguel Gonzalez, and Bud Norris. Kevin Gausman is another option, and Showalter has already said that he is not on an innings limit this season. Or both Norris and Gausman could start, with Chen taking a seat against a righty-heavy Tigers lineup. Ubaldo Jimenez is also on the roster, but it's unlikely that he will be in the rotation.
As a whole, the Orioles' rotation defied plenty of statistical trends. They struck out just 6.93 batters per nine innings, the fifth-worst rate in the American League. Only the Kansas City Royals' starting five struck out a lower percentage of hitters and still made the playoffs. The Orioles also had the third-highest home run rate in the league, in large part thanks to the cozy confines of Camden Yards. Their walk rate was the fourth-highest in the AL. With the O's ranking in the bottom third in the AL in all three true outcomes, it comes as no surprise that their 4.19 FIP was the second-highest in the league. Despite the concerning trends, the rotation had a 3.63 ERA, sixth-best in the AL. Their ERA-FIP of -0.55 was the most favorable difference in the league. The Tigers were at the opposite end of the spectrum at 0.54, second-worst in the AL.
RHP Chris Tillman (13-6, 3.34 ERA)
Tillman is the unquestioned ace of the Orioles' staff, and for the last four months, he has pitched like one. As Beyond the Box Score pointed out last week, Tillman was awful through June 5th. He gave up a 5.20 ERA and 4.89 FIP through his first 13 starts, the last of which was a one inning, five run mess against the Texas Rangers. Since then, Tillman has made 21 starts. He allowed four earned runs just one time. Tillman has a 2.38 ERA and 3.56 FIP in his last 136 1/3 innings. He struck out 17.2 percent of batters, or 6.27 per nine innings, during that stretch. The more impressive improvement was a sharp decrease in walk rate, from 10.0 percent of batters during the first two months of the year to just 6.2 percent afterward.
One major improvement in Tillman's game from years past is his ability to limit home runs. He allowed 33 home runs last season, the third highest total in the American League. This year, Tillman's home run count is down to 21, the 15th highest total in the AL. The homers are never going to completely go away, as Tillman is one of the most extreme fly ball pitchers in baseball. He ranked 13th in the AL among qualified pitchers this year with a 39.3 percent fly ball rate, which was actually the lowest mark of his career. Tillman relies heavily on a four-seam fastball and despite its velocity -- he sits around 91-92 miles per hour -- loves to use it up in the zone. This helps change hitters' eye levels for his 12-6 curveball, which generates a lot of weak ground balls but not many whiffs. The curveball is his go-to pitch with two strikes, but he also likes to mix in his changeup against both right and left-handed hitters.
LHP Wei-Yin Chen (16-6, 3.54 ERA)
Despite throwing 22 fewer innings than Tillman, Chen led the O's with 2.6 fWAR this year. His 3.89 FIP was second to only Kevin Gausman, who only logged 113 1/3 innings at the major league level. Chen was also arguably better than Tillman in the second half, posting a 2.76 ERA and 3.22 FIP after the All-Star break. The lone lefty in the Orioles' rotation, Chen's platoon splits were relatively even in 2014. Righties hit for more power, including 20 of the 23 home runs that Chen allowed. Surprisingly, lefties had a slightly higher batting average at .268 compared to .266 for righties. The Tigers led baseball in batting average and OPS and were second to the Orioles in ISO against left-handed pitchers this year. This may lead Buck Showalter to stick Chen in the bullpen, allowing him to pick his spots with the talented lefty.
Chen's fastball isn't dominant, but at 92-93 miles per hour from the left side, can be quite effective. He threw it nearly two-thirds of the time, primarily relying on a four-seamer. Chen also had a high fly ball rate, but at 37.5 percent (15th in the AL) was slightly less reliant on fly outs than in seasons past. His home run rate was nearly identical to last season. Surprisingly, he was no more homer prone at the hitter-friendly Camden Yards than he was on the road. Chen also uses a slider, curveball, and splitter, but saves the latter for use against right-handed hitters. Opposing batters hit just .215 against the slider this season, compared to .290 and .317 for the curveball and splitter, respectively.
RHP Miguel Gonzalez (10-9, 3.23 ERA)
At 30 years old, Gonzalez is the oldest member of the Orioles' playoff rotation, though also one of its least experienced. His 430 2/3 career innings trail Tillman, Norris, and Chen. Regardless, Gonzalez was a solid mid-rotation starter during the first half of the season, allowing a 4.56 ERA through the end of June, though his 5.29 FIP was a concern. His peripheral numbers didn't improve much during the second half, resulting in a 4.69 FIP after July 1st. However, Gonzalez gave up only 20 earned runs in his final 12 starts, resulting in a 2.22 ERA. He held the opposition to three runs or fewer in 11 of those 12 starts, picking up 10 quality starts along the way. Gonzalez received just 3.9 runs per game of support from the Orioles' offense this season, so it comes as no surprise that the team was just 7-5 during his excellent run down the stretch.
Gonzalez was the most homer-prone Orioles pitcher this year, allowing 25 long balls in just 154 innings of work. He allowed a higher percentage of fly balls than either Tillman or Chen, ranking seventh in the AL with a 42 percent fly ball rate. Gonzalez doesn't throw his fastball as often as either of them, but still uses either a four or two-seamer over 50 percent of the time. He also relies on a slider and curveball that both generate their fair share of ground balls, but neither should be considered a bonafide strikeout pitch. Gonzalez's splitter induces the highest swing-and-miss percentage of any of his pitches, but tends to go a long way when he can't locate it. Opposing batters hit .267 and slugged .486 off the splitter in 2014.
Bud Norris (15-8, 3.65 ERA)
You could argue that Norris was the Orioles' second-best starter in 2014. He finished well behind Chen, Tillman, and Gausman was 1.5 WAR, but his 3.98 xFIP was second on the team, behind only Chen. He didn't have the eye-popping second half numbers that Tillman did, but Norris was the team's most consistent starter in the first half. He has a 3.96 ERA in 15 starts before the All-Star break, behind only Gausman's 3.29 ERA (in seven starts). Norris' 2.14 strikeout-to-walk ratio was third on the team, while his 16.5 percent strikeout rate was fifth -- fourth if you exclude probable bullpen arm Ubaldo Jimenez. While he didn't strike out a ton of guys overall, he did tend to collect them in bunches. Norris had 10 starts with six strikeouts or more, and 34 in his final 30 1/3 innings of the year.
Norris led the Orioles' staff with a 42.2 percent ground ball rate in 2014, but he still fits the mold of a fly ball pitcher. His 37.2 percent fly ball rate was nearly identical to Chen's 37.5, and Norris coughed up 20 home run balls this year. Surprisingly, 15 of those 20 home runs came away from Camden Yards. Norris has always had huge home/road splits throughout his career, but early on that was chalked up to the spacious outfield dimensions of Minute Maid Park. Norris continued that trend this season, allowing a 2.44 ERA and 3.44 FIP at home compared to a 4.80 ERA and 4.97 FIP on the road. These severe splits could lead Buck Showalter to give Norris the nod in Game 2 at home. The home cooking didn't seem to be a problem for the Tigers back in May, though, as they were eventually able to plate four runs on Norris in 7 1/3 innings in a 4-1 victory.
Kevin Gausman (7-7, 3.57 ERA)
An ace in the making, Gausman is the wild card of the Orioles' playoff rotation. The club kept him on a strict innings limit to start the season in order to keep him fresh for the stretch run, and his September numbers show no signs of slowing down. He put up a 2.87 ERA and 2.97 FIP during five September starts, tallying 29 strikeouts to nine walks. This was par for the course throughout the second half, when he gave up a 3.72 ERA and 3.35 FIP as a full-time member of the rotation. He struck out just 18.5 percent of the batters he faced this year, down from 24.4 percent in 47 2/3 innings last season. Gausman was also the stingiest Orioles starter when it came to allowing home runs. He gave up seven home runs, or just over one every 18 innings pitched.
The conundrum surrounding Gausman may not be his youth and innings count, but rather his pitching arsenal. With a fastball that averaged 95.82 miles per hour during the regular season, Gausman projects as the prototypical high-octane late innings reliever that can overpower the middle of a lineup in a tough spot. He can exclusively use the fastball and splitter in a relief role, ignoring the slider and changeup that he used sparingly as a starter this season. The splitter was Gausman's best pitch according to Fangraphs' pitch values, coming in at 2.1 runs above average for the year. Opposing batters hit just .195 with a .286 slugging average during the regular season.