There’s been a lot of focus on Cleveland Indians hurler Cliff Lee for his amazing come-around in the early going this season. But staff ace C.C. Sabathia and last year’s no. 2 starter, Fausto Carmona, have both struggled in the early going. What’s been amiss with the pair of hurlers who helped get the Tribe to the postseason last year, and what can be done to turn them around?

First, let’s look at Sabathia, last year’s Cy Young Award winner. On April 16, he allowed nine runs in just four innings to the Detroit Tigers, bringing his ERA up to 13.50 and his record down to 0-3. From April 22 onward, Sabathia has thrown 36 1/3 innings with more than five times as many strikeouts as walks and only one home run allowed. His ERA has fallen all the way down to 5.47. This sudden reversal came about immediately as well: After the Tigers pounded him on April 16, Sabathia struck out 11 Royals over six innings less than a week later. Obviously, something changed in the ace’s approach — namely, the use of his slider.

Thanks to advances in statistical databases brought about by MLB’s own Pitch f/x system, analysts are able to break down the structure of a pitcher’s pitch selection and approach. Through his first four starts, Sabathia leaned heavily on his fastball, throwing it 67% of the time. This was more often than he threw it in 2007, when he utilized it 60% of the time. While this may not seem significant at first glance, those extra fastballs came at the expense of other pitches that could have been mixed in. In this case, it was at the expense of Sabathia’s slider.

Since that pounding at the hands of the Tigers, Sabathia has brought his overall slider usage back to 20% from a low of 8%, achieved between March 31 through April 16, and his opponents have once again struggled to score off of him, culminating in Wednesday evening’s complete-game shutout of the Athletics, when he struck out 11 hitters and walked a pair while scattering five hits. He’s brought his overall opponent line down as well, thanks to keeping hitters at a .220 AVG/.270 OBA/.295 SLG level since April 22.

His fastball, which Sabathia struggled to command during his rough stretch, is at the same level of use as in the past as well. This change can be seen in his home-run data: He gave up five homers in 18 innings thanks to his poor location — essentially putting his fastball in the hitter’s wheelhouse to avoid throwing it out of the zone — but he’s now dipped his HR/9 to an even one per nine, and pushed his homers per fly ball back toward his career rate of 8.6 with a 10% rate.

If Sabathia keeps his peripherals in order, there’s no reason he won’t bring his ERA back down to the levels we are used to seeing. His QuikERA (QERA) — a statistic developed at Baseball Prospectus that is more accurate for determining future ERA than ERA itself due to the components involved with it — is 3.82. That is 1.65 runs better than his actual ERA, and a solid indicator of where we can expect him to end up.

His teammate, Carmona, however, could be on a different path. Carmona had his own excellent 2007 campaign with a 19-8 record, 3.06 ERA, and more than 200 innings pitched. He has seemingly started this year off on the same path with a 2.40 ERA, but there are problems with relying on ERA to gauge a pitcher’s production. QERA tells us that Carmona’s ERA should be closer to 6.70 — in the realm of replacement pitchers, not aces. This lofty figure was derived from his strikeout totals, his walk rate, and his ground-ball rate. Carmona is only punching out 3.3 hitters per nine, down almost 2.5 strikeouts per nine from last season. He’s also dealing free passes to first to an insanely high 6.5 batters per nine — four full walks more on a rate basis than he did in 2007. If not for his extreme ground-ball tendencies, Carmona would have an ERA closer to his QERA.

In 2007, Carmona’s ground-ball/fly-ball ratio was three to one, a total that helped him dominate the opposition despite league-average strikeout totals. This year, he’s lost some of those strikeouts, but replaced them with more ground balls — his G/F ratio for 2008 is a Brandon Webb-like 3.7. Thanks to the Indians’ defense — which is currently converting 71.4% of all batted balls into outs, ninth in the majors as measured by Baseball Prospectus’s Defensive Efficiency — Carmona has pitched well even with the poor walk totals.

The data gives you the idea that Carmona is, to a degree, intentionally throwing the ball out of the zone. He has increased his sinking fastball usage to 82% from an already lofty 75%, and with this rise in sinkers has come a rise in G/F ratio. According to Pitch f/x, Carmona has given up just nine extra-base hits on the season. The opposition’s Isolated Power — a figure derived from subtracting batting average from slugging percentage — is just .063 against Carmona, a number that makes even Dodgers speedster Juan Pierre look like a middle-of-the-order bruiser by comparison in the abstract. The data shows that Carmona loves to go high with his sinker; when hitters bite, they get on top of it and hit a grounder, or they just let it go for a ball.

This has been the key to Carmona’s success, and to his credit, it has worked. The problem is that with viewings of game tape and data such as that of Pitch f/x, it is not the kind of success that is guaranteed to work long-term. Like his teammate before him, Carmona should get to a stage where he needs to mix up his pitches more, or see his production drop precipitously — as his QERA suggests. Cleveland’s pennant chances rest on the production of this pair of quality arms. But perhaps, like Sabathia, Carmona’s issues will only be fixed once he’s deemed broken.

Mr. Normandin is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit BaseballProspectus.com.