The last two weeks marked an awful stretch for the Detroit Tigers' pitching staff, as a 3-8 record since May 19 has seen Detroit surrender an average of 7.1 runs per game.

Surprisingly, the culprit of the losing streak was the starting pitching, which has been a strength for the Tigers during a span of reaching the American League Championship Series three years in a row. Detroit starters notched just two quality starts during the 11-game stretch (both by Anibal Sanchez), and surrendered five or more runs seven times.

Despite the recent struggles, four of the Tiger pitchers have shown flashes of greatness throughout the last 14 months, whether it was Max Scherzer winning the Cy Young Award or Justin Verlander dominating the Oakland Athletics in the ALDS.

Though Scherzer, Verlander, Sanchez and Rick Porcello have all cemented themselves as quality starting pitchers, which one of them is the best?

As Detroit enjoys the top record in the AL through 50 games, here is the case for all four righties, keeping in mind their performances from last season, the 2013 playoffs and the first stages of 2014. Last season's statistics will provide the most recent sample of each pitcher's performance over an entire season, while the playoff numbers demonstrate their best efforts when the games matter most.

Justin Verlander

The title of "ace" in Detroit is Verlander's to lose. With a career ERA of 3.43 and 142 wins as a Tiger, Verlander has maintained his place atop the pitching staff by starting on Opening Day for seven straight seasons. The 31-year-old not only brought a Cy Young Award to the city of Detroit, but also the first MVP for a pitcher since 1992.

Verlander's track record is undeniably the best in the Tigers' rotation, but his regression over the past two years has been alarming for a club that recently signed him to a 10-year, $219.5 million contract.

2013: 13-12 record, 3.46 Earned Run Average, 218.1 innings pitched, 217 strikeouts

Last season began a stretch in which Verlander no longer looked like the pitcher who won the MVP Award in 2011. After pitching well through the month of April, an eight-run blasting at the hands of the Rangers on May 16 seemingly threw Verlander off his groove. He allowed five or more runs five times in the three months after that start, and finished with his worst ERA, fewest wins and fewest strikeouts since 2008.

2013 Playoffs: 1-1, 1.13 ERA, 23 IP, 31 SO

When the postseason began, the Tigers went with Scherzer to pitch Game 1 of the ALDS, but Verlander ultimately pitched like the ace in Game 2 by holding the A's scoreless in seven innings. For his sequel, the veteran took the mound in Game 5 when the Tigers were desperate for a win and threw eight two-hit innings with 10 strikeouts in Detroit's 3-0 win.

Even in the series loss to the Boston Red Sox, when the Tigers were eliminated from the postseason, Verlander dominated in his only start. He allowed his only run of the playoffs on a seventh-inning home run to Mike Napoli, and finished with 10 strikeouts in eight innings.

Verlander showed that he can still be the best pitcher in baseball when the occasion demands it, as he surrendered just 10 hits in 23 postseason innings. Brad Ausmus knows he can count on Verlander to be a workhorse, as he threw an average of 116 pitches in those three starts.

2014: 5-4, 4.04 ERA, 71.1 IP, 50 SO

Perhaps the most alarming aspect of Verlander's struggles is that the carryover into 2014 turns 2013's "anomaly" into a trend. Verlander's strikeouts have noticeably decreased from this time a year ago, when he fanned 82 hitters through his first 11 starts. He has yet to showcase a dominant performance, allowing two or more runs in each start but one, when he lasted just five innings while shutting out the Indians.

Fans around Detroit panicked last season when Verlander struggled, but he still managed to record seven starts of six or more shutout innings. In 2014, the former MVP is on pace for zero.

Max Scherzer

While Verlander experienced setbacks throughout 2013, Scherzer was enjoying a breakout year in which he took home the AL Cy Young Award. 2014 holds major implications for the 29-year-old's future as he tries to show that he can maintain that level of dominance.

2013: 21-3, 2.90 ERA, 214.1 IP, 240 SO

There was little dispute over who was the best pitcher in the AL last season, as Scherzer led the league in wins and posted career bests in ERA, WHIP, strikeouts and innings pitched. Scherzer decreased his ERA and WHIP for the third straight season and became the most important pitcher on the Tiger staff in wake of Verlander's down year. The electric right-hander has every opportunity to name himself the ace of the staff with a repeat performance in 2014, but one strong season isn't enough to dethrone a consistent contributor like Verlander.

2013 Playoffs: 2-1, 2.82 ERA, 22.1 IP, 34 SO

The faith that manager Jim Leyland developed in Scherzer was apparent when he called on him in relief during Game 4 of the ALDS with the Tigers on the brink of elimination. One of the greatest images of the postseason was Scherzer celebrating after escaping a bases-loaded no-outs jam en route to a victory that kept Detroit alive. Scherzer was also great in his three October starts, picking up three quality starts and striking out 34 batters.

2014: 6-1, 3.00 ERA, 72 IP, 82 SO

Through nine starts Scherzer was probably the frontrunner to win another Cy Young Award, boasting a 1.83 ERA and six wins. But the righty has allowed 12 earned runs in his last two starts to balloon his ERA to an even 3.00 amidst a difficult stretch for the Detroit pitching staff.