The usual suspects are in their reserved spots atop the lists. Yes, Matt Kemp is slugging homers left and right and driving in runs like the one-man wrecking crew he proved to be last season. And of course, Roy Halladay has simply refused to let anyone get on base, and he's been even more stubborn about letting them score. No surprises there. No questions asked.

Look a little deeper, though. There are plenty of surprises to be found, and there are plenty of questions to be asked. The Dodgers have won how many games already? Tim Lincecum's ERA is what? Aaron Harang struck out how many batters in a row the other night? Heath Bell did what?

The questions go on. Is Barry Zito's apparent resurgence for real this time? Are Stephen Strasburg and the Nationals, owners of a Major League-low 1.99 staff ERA, putting together one of the best pitching staffs in baseball? Can Yoenis Cespedes make up for his low average and high strikeout numbers with his raw power? Can the Cardinals' hitters, putting together a Major League-high .863 team OPS, stay hot?

There will be another important question this week, one that will heat up and cool down most likely based more on what is said off the field than what happens on the diamond: After a spring full of verbal jabs from new Red Sox manager Bobby Valentine and a great deal of talk about how the rivalry is changing, how will the first Yankees-Red Sox series of 2012 play out this coming weekend at Fenway Park?

And when does a hot start become something more? When can we call a slow start a bona fide slump?

But first, there are other questions to be answered. On the injury front, how long will Red Sox center fielder Jacoby Ellsbury be out with a partially separated right shoulder? Who will the Giants turn to in the ninth inning now that Brian Wilson, their eccentric and bearded closer, needs a second Tommy John surgery and is likely done for the year?

We'll learn more about the latter starting Monday, when the Giants welcome the Phillies to AT&T Park with their respective aces on the mound. Can Halladay (2-0, 0.60 ERA) keep up this pace against a surprisingly effective Giants lineup? Is Lincecum (0-1, 12.91 ERA) really in trouble?

"He left a lot of pitches up, a lot of mistakes when he was ahead in the count," Giants manager Bruce Bochy said after Lincecum's last start, the shortest of his big league career at 2 1/3 innings. "Tough time putting some hitters away."

About 11 hours before that series begins in San Francisco, the Rays will have to prove whether their highly touted pitching staff is up to the challenge of stopping the streaking Red Sox, who have won three in a row against their American League East rival. Boston has outscored Tampa Bay, 31-11, so far this series, and the Red Sox will have a chance to lock up an early-season sweep on Patriots' Day at Fenway Park.

"They're on everything right now," Rays manager Joe Maddon said Sunday. "They're swinging the bats aggressively. They're not missing their pitch and fouling it off. They're spitting on borderline pitches. They're very much locked in as an offense right now."

If you want to talk about being locked in, though, the conversation must begin with Kemp. The 2011 National League MVP runner-up is crushing everything that comes his way. He's hitting .487 with a 1.548 OPS. He has six homers and 16 RBIs. He's scored 13 runs. Even worse for the rest of the NL, Andre Ethier has been almost as good, batting .289 with a 1.030 OPS, three homers and 15 RBIs. How long can Ethier and Kemp maintain this torrid pace?

"[Kemp's] pretty hot -- we've pretty much seen this from him most of the year," Dodgers manager Don Mattingly said. "He's not going to be able to keep up this pace, I'll say that. But it's legit. You don't just do some of the things that he's been doing."

Thanks to those two and the Dodgers' thus-far excellent pitching, which includes Harang's nearly record-breaking nine consecutive strikeouts Friday night, Los Angeles has jumped out to a Major League-best 9-1 record. It'll get a chance to improve on that this week against the Brewers and Astros, starting Tuesday when Chad Billingsley (2-0, 0.63 ERA) faces Yovani Gallardo (1-1, 5.91).

The Rangers are set to run the gauntlet of elite American League teams, starting this week with the Red Sox and the Tigers. From there, they get the Yankees and the Rays. Are the defending AL champions ready for the challenge?

"They're chasing us," Rangers second baseman Ian Kinsler said. "It shouldn't matter to us. We're not chasing them. Obviously they are some of the best teams in the American League, but we feel like it's got to come through us. We just have to play good baseball."

There are questions in the NL East as well, though apparently not on the Nationals' pitching staff (MLB-leading 98 strikeouts and .186 average against), as they've jumped out to a 7-3 start. When the Marlins welcome the Cubs to Little Havana and travel to face Washington, how will Miami respond to Ozzie Guillen's return from his suspension?

How about the NL Central? The defending World Series-champion Cardinals are off to a hot start at the plate -- they lead the Majors with 57 runs scored -- thanks to David Freese, Yadier Molina, Carlos Beltran and company. Can they keep it up this week against the Reds and Pirates?

At 6-3, the Tigers will start the week with the lead in the AL Central -- no surprise considering they were widely picked to dominate the division. But the Indians, for all their pitching struggles, are averaging 6.5 runs per game. And the White Sox, for all their recent difficulties against division foes, have won five games against AL Central opposition. How long will this last?

All the questions boil down to something much more simple: Can the hot starters stay hot, and will the early slumps be broken?

There are plenty of those questions left to be answered, and fortunately, there's plenty of baseball yet to be played.