The Yankees/Red Sox rivalry continues tonight at Fenway Park. Becoming sick of the hype is the fashionable thing to do, but let’s face it: these have been the two most successful franchises of the post-strike era by any measure. They have a history that goes back a century and includes some of the defining moments in baseball history, and even in recent years, they’ve given us entertaining, exciting baseball, with races that would be considered classic were it not for the Wild Card. For all of the backlash, games between the two teams are consistently the highest-rated ones of the year on ESPN. The Tampa Bay Rays are certainly in the picture, but the most likely scenario in the AL is that these two teams both get back to the postseason once again.

Tonight’s game is particularly enticing, because each team’s top young starter takes the mound looking to improve upon shaky early-season performance. Joba Chamberlain struggled with his command and pitch selection a week ago at Yankee Stadium, failing to escape the fifth inning in the game that the Yankees eventually won, 6-5. This is just his third start of the season, as the Yankees have worked to keep CC Sabathia on a five-day schedule. Jon Lester has been knocked around a bit as well, to the tune of a 5.50 ERA, though a 19/5 K/BB is an indication that the problem is correctable: Lester’s .388 batting average on balls in play has nowhere to go but down.

As attractive as it is, the Chamberlain/Lester matchup will only hold my attention for about one hour, because the night’s true headline game, the headline pitching matchup, starts at 8:10 ET. That’s when Zack Greinke takes the mound against the Tigers looking to extend his scoreless-innings streak into the 40s, while continuing his delayed ascension to the top tier of starters in MLB. The bifurcated nature of his career-Greinke is pitching in his sixth season at age 25, but missed almost all of 2006 due to social anxiety disorder and spent a big chunk of 2007 in the bullpen-and pitching in the dead zone of Kansas City have hidden just how effective he has become. Since 2007, Greinke has a 3.35 ERA in 344 1/3 innings with a fantastic 315/91 K/UIBB ratio. The creative approach to pitching that made him a prodigy has been leavened with experience; when combined with the raw skills he’s always had, it makes for a pitcher who’s ready for stardom.

Greinke has famously opened the ’09 season without allowing a run in his first three starts, striking out 26 men in 20 innings, walking just five. His last outing was a shutout of the power-laden Texas Rangers in which he threw just 35 balls in 111 pitches. He’s also shut down the White Sox and the Indians, two teams that can hit the long ball. The matchups are worth mentioning because Greinke is a fly-ball pitcher who, when he gets beat, gets beat with extra-base hits. His current seven-start run without allowing a homer is unusual-his previous longest stretch was four, back in 2005. It’s not a stretch to suggest that the addition of Coco Crisp to the Royals‘ outfield has helped him as well; Greinke’s allowed just three doubles and a triple so far.

Greinke’s fly-ball tendencies mean that his chance to break Orel Hershiser‘s consecutive shutout streak is small, because it takes just one wind-blown fly ball to end a streak like this. Hershiser was a ground-ball pitcher making home starts in Dodger Stadium in 1988; Greinke is in a much tougher spot, allowing more fly balls to stronger hitters, and to more home-run threats, in an era and a home park where fly balls leave the yard. If he does manage three more starts without allowing a run, his achievement will surpass those of Hershiser and Don Drysdale because of the context of the modern game.

A streak extended or broken won’t define Greinke’s season. No, he’s going to be one of the best starters in the AL, and one of the most entertaining to watch, because of how he combines stuff, command, and creativity in retiring hitters. He’s smaller than Mike Mussina, but that’s who he reminds me of most, a right-hander with a great curve who is, quite frankly, smarter than the game.

The thing is, he may not be the highest-upside starter in tonight’s contest. Pitching for the Tigers is Rick Porcello, the right-hander who was the team’s #1 pick in 2007. Porcello’s rise to the majors parallels Greinke’s in some ways; both were #1 picks, both reached the majors less than two seasons after being selected at age 20, and both arrived on teams in desperate need of quality pitching. The two both had fantastic control for high-school draftees, and both had good mechanics and a feel for pitching.

Porcello, however, has an extra few mph on his fastball, peaking up around 97 and working in the mid-90s, while Greinke not only didn’t top out as high, but worked at a speed considerably lower. Porcello is a strong and potentially extreme ground-ball pitcher who throws a low-90s sinker and a four-seam fastball, and whose breaking stuff is still being managed carefully due to his age. He has a little more of a pitcher’s build than Greinke did, then or now. At the risk of being laughed out of the room, here are two stat lines. One is Porcello’s last year in the Florida State League. The other isn’t.

             Age  Lvl   IP    H   BB   SO  HR
Porcello      19   A+  125  116   33   72   7
Not Porcello  19   A   186  176   52  125   9

Porcello gets ground balls. Lots of them. He throws strikes, lots of them. The combination should enable him to get through innings without throwing pitches, lots of them. Moreover, the reliance on a fastball/sinker combination should serve to leave his elbow and shoulder intact, as opposed to the joints of pitchers who rely on breaking balls.

Maybe I shouldn’t invoke the name “Greg Maddux.” Maybe that’s silly for a guy with two major league starts. But Porcello brings the ground balls-23 in those two starts-and the strikes-one walk in 12 innings so far. Because he doesn’t strike out a lot of batters yet and he keeps the ball on the ground, his short-term stats-ERA and hits allowed and the like-might be higher than Greinke’s were. They might even be ugly, maybe something like a 5.59 ERA and 225 hits allowed in his first 187 innings pitched. One he gets established, though, and the Tigers ease him through the injury nexus, you’ll have one of the best starters in the game, someone with the kind of upside that makes you save the ticket from the first time you saw him pitch.

So let the cameras and the websites and the newspapers converge on Fenway Park tonight. It’ll be a good game, with some terrific talent on display, and two good, young pitchers throwing. If you really want to see the future, though-if you really want to catch the best game of the night-look to the Midwest, sit back, and enjoy.